KB5065426 update stops file and print sharing from working

Kevin OBrien 195

I was having issues with multiple locations using windows file and print sharing with password sharing. I found windows update KB5065426 was installed and that my file and print sharing options were turned off. I also found that networks were set to public that had previously sent to private.

Even after setting the settings back, the computers would not working with file and print sharing and I had to uninstall the update to get the functionality to work.

Eugene Mollentze 55 Reputation points

2025-09-11T07:09:26.28+00:00

Morning. This same issue happened on my sites. the ONLY way to make it working again is to uninstall the kb5065426 update. Even after doing as mentioned above, the issue persists.

This is something that needs to be avoided in regards to we who have large sites/organizations that we need to run.

Please let us know if there is a fix for this. the stress is through the roof at the moment.
TSENG 145 Reputation points

2025-09-11T09:05:36.2866667+00:00

There are thousands of computers in the company Sharing files and printers this way is causing chaos after the KB5065426 update! Help! Microsoft - wake up and fix this issue!
олексий горбатько 85 Reputation points

2025-09-12T07:13:39.54+00:00

After installing this package, when I try to access a shared folder, the system asks for a login and password. I enter the credentials in the format server\username and the correct password, but Windows keeps showing an error: "The username or password is incorrect." I am sure the credentials are 100% correct. This seems to be a Windows issue.
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Michael Burk 45 Reputation points

2025-09-12T08:29:05.49+00:00

We are experiencing the same issue and the fault is definitely rooted in the SID. Two machines with the same SID can't authenticate. Our solution is to create a new Windows User, which also get's a new SID. Or reset the current user with "Sysprep".
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Winuker 0 Reputation points

2025-09-12T09:44:56.4566667+00:00

Microsoft deberia revisar esto, no se puede permitir tal error.
олексий горбатько 85 Reputation points

2025-09-12T11:04:57.34+00:00

Yeeay man the problem is the same SID.

THANKYOU
Tainã Andrade 0 Reputation points

2025-09-12T13:40:32.2333333+00:00

I have the same problema here. With a lot of PCs
Giulio Gaudio 55 Reputation points

2025-09-12T15:12:44.2733333+00:00

Adding a new user the SID remains the same, exception the latest four digit that increase but are UNUSEFUL to solve the SHARE problem that remains because all the inital characters of the SID are the SAME for ALL the new users yet create.... last four digits are 1001-1002-1003 for each new user you will add. So problaby the MASTER part of SID it is create by OS during installation prcedure.
Dwight Dingus 5 Reputation points

2025-09-12T16:47:19.4+00:00

Removing it worked for me! Many thanks!
Eric Joris 0 Reputation points

2025-09-13T12:22:28.9766667+00:00

Same problem here.
Clif 5 Reputation points

2025-09-13T14:39:58.5066667+00:00

I have same issue with KB5065426. I have tried all the suggestions and to no avail. the only solution at this point is to remove the update.

For those that do not that savvy about windows, be aware that you do not want to do use the recovery option, you want to go to update history and scroll down to the related setting section and click on uninstall updates. here a list of the recent updates will appear. they will be sorted by date and newest may be on the top but not always. Pay Attention to the dates and look for KB50655426

but if you do not pause the updates, it will reinstall it within hours in my case. i have paused updates for as far out as you can, seems different computers offer different lengths you can do this.

hope fully in the next couple of weeks Microsoft will have a new update that fixes this issue.
Nicholas Page 251 Reputation points

2025-09-13T16:35:18.81+00:00

Facing this exact issue on two (non-preview now) system at home, one was cloned from the SSD of the other and I just changed the name and Windows license etc and has been working fine for years until now...all file/printer sharing and RDP is dead, just keeps saying incorrect user/pass. All the normal stuff is verified, private network, sharing on, etc etc and certain it is due to the update plus same SID as follows:

I verified both machines do have the same SID.

I tried uninstalling KB5065426 from both systems but that did not resolve.

Next I removed KB5064081 from both systems and reboot and now SMB/RDP is working normally again.

In my process of troubleshooting I found that the Remote Desktop Classic Windows app actually still worked also but, the regular RDP would not, so the RDP Classic app must authenticate differently? I'm not sure if you can even get or install this still since the newer "Remote Desktop" app is depreciated and maybe not working at all.

I am considering trying SIDCHG on one of them as a long term solution since I assume Microsoft will not make any attempt to revert this dispite what will likely be millions of impacted systems. Please us know if you tries SIDCHG and any problems or side effects or other issues are encountered.
Steve Gutteridge 10 Reputation points

2025-09-14T11:05:21.47+00:00

This update has killed the Samba 1 share on my Buffalo Link station NAS, on two different machines. Tried everything but only uninstalling this update has worked.
LOUIS LOPEZ 10 Reputation points

2025-09-14T15:43:01.4733333+00:00

The update is now not removable. It is part of the OS and cannot be uninstalled now. I have 3 duplicate SIDs because I bought computers from china that were cloned. I need a SID changer or reload the OS from scratch to fix my issue. It is not an SMB 1.0 or any SMB issue. Microsoft has blocked duplicate SIDs from being able to communicate with each other.
LUIS MIGUEL CALDERON GAVIRIA 0 Reputation points

2025-09-15T07:37:03.6266667+00:00

hola!! el problema persiste por mas de que elimine la actualizacion o haga lo que considere medianamente bien, pero seguimos con el problema. dos equipos con el mismo problema con actualizaciones todos los dia.
GJO 0 Reputation points

2025-09-15T17:58:34.3+00:00

After install that update "KB5065426" I get two laptop with BitLocker enable that now is asking for the recovery key every time is turn on the laptop and it doesn't matter if you enter the recovery key it keep asking for the key.

The only way is if you hit "skip" Windows boot and try to repair the Bitlocker but ending asking for the recovery and after enter the key Windows come up but the problem stay.
Paul Woodward 10 Reputation points

2025-09-16T02:20:15.8+00:00

Here is a solution I found. I did use SIDCHG (https://www.stratesave.com/html/sidchg.html)

Step 1. Uninstall any antivirus, then disable Defender

Open Windows Security → Virus & threat protection.

Under Virus & threat protection settings, click Manage settings.

Toggle Real-time protection → Off.

Step 2. Run SIDCHG from CMD prompt as Admin.

sidchg64-3.0m.exe /R

You can use trial key (78@5i-QwUJM-woQEE-Kv). Verify on their web site as it may change.

Step 3. Reboot then reinstall antivirus.

Note: I checked SID before and after using Power Shell:

(Get-CimInstance Win32_UserAccount -Filter "Name='$env:USERNAME'").SID -replace '-\d+$',''

This worked for me for 2 clients, good luck!
Steve Taylor (Staff) 5 Reputation points

2025-09-16T09:37:04.4766667+00:00

We also have major issues with this update. It stops certain software being run from mapped drives and breaks some of our printers. The fixes suggested do not make any difference on our system and we don't have duplicated SIDs.
David 0 Reputation points

2025-09-16T11:32:51.1566667+00:00

We're having the same problem on two computers. They haven't been cloned, but they have the same SID. I tried with a new user with a different SID, and the problem persists.

The problem is since the installation of kb5065426
LOUIS LOPEZ 10 Reputation points

2025-09-16T13:48:29.74+00:00

I removed the patches on three computers and something triggered that the patches are no longer removable even using powershell. Microsoft throws an error that the patches are now required and cannot be removed.
Mike Horton 0 Reputation points

2025-09-16T18:37:29.57+00:00

I have been having problems on two networks. First started on one printer sharing stopped working, \computername asked for password, entered uname and password. Said password was wrong, I knew it wasn't. Today another network called with file sharing issues. After numerous hours looking for a solution, I began looking at windows update and discovered that some computers had received KB 5065426 and some had not. I decided to remove it and file sharing came back. I then went directly to the network with the print sharing issue, and removed that update and printing was restored. I know we are supposed to keep things safe for the clients, but honestly, nothing working is not the answer. Find another way Microsoft, cause this is not helping anyone. I now have clients that are asking me to get them away from Microsoft products.
Amina Mubarak Hamad 0 Reputation points

2025-09-17T08:16:42.21+00:00

We are facing the same issue. workstations has different SIDs.. uninstalling the update using command 'wusa /uninstall /kb:5065426' solved the file sharing issue.

hope that Microsoft will urgently provide another update solving the issue as SMB and file/ print sharing are very important for organizations
Steve Gutteridge 10 Reputation points

2025-09-17T10:18:27.2633333+00:00

The exact same issue occurs on Windows 10 with update KB5065429, and the above "Answer" doesn't work on that either.
Clif 5 Reputation points

2025-09-17T16:09:30.5033333+00:00

just published on https://www.bleepingcomputer.com/news/microsoft/microsoft-says-windows-september-updates-break-smbv1-shares/ Microsoft is now working to resolve this issue, and until a fix is available, it has provided impacted customers with a temporary workaround.

This requires them to allow traffic on TCP port 445, which will cause the Windows SMB connection to resume successfully by switching to using TCP instead of NetBT.

read article for more details. but even though it says SMB1 I think it affects SMBv2 also.

i removed the update and am going to pause updates until the fix comes out.
Steve Gutteridge 10 Reputation points

2025-09-17T18:00:54.4566667+00:00

I already have port 445 open and it doesn't help.
Rameo64 0 Reputation points

2025-09-17T20:51:08.0166667+00:00

I uninstalled the kb:5065426 via powershell on my laptop and mini, that I use as a server with all of my hard drives attached to. I can't connect to the computer or the hard drives, but I can connect to my mini computer via RDP. Any ideas how to get back to my mini computer?
Brad 0 Reputation points

2025-09-18T02:48:13.9333333+00:00

Update has reinstalled and now even using that command doesn't uninstall update.
Amina Mubarak Hamad 0 Reputation points

2025-09-18T04:54:39.54+00:00

try to run:

'sfc /scannow' then 'dism /online /cleanup-image /restorehealth'
Aeris_Valetine 20 Reputation points

2025-09-19T00:54:41.4233333+00:00

me too, i have de same problem now
Antoin Currie 0 Reputation points

2025-09-19T09:24:53.42+00:00

DFS Replication for me also broke after installing this update
Steve Taylor (Staff) 5 Reputation points

2025-09-22T15:32:37.3533333+00:00

Just to update on our situation within our environment. ctl3d32.dll was the culprit for our issues as KB5065426 removes the file from the windows system folder / folders. This stopped our revelation database system from working.
Joseph Cavallaro 10 Reputation points

2025-09-24T21:48:59.99+00:00

So at first we were thinking it was a DNS issue but it is related to the update. A workaround that seems to be consistently working is to map the drives by IP address vs. name.

Removing the update does require a sfc /scannow to be run on almost every machine we have removed the update from.
GJO 0 Reputation points

2025-09-24T23:08:32.6+00:00

Hi,

Do someone has tried to create a new rule in the Windows Defender Firewall with Advanced Security under Inbound Rules and Outbound Rules for the port 445 to give full access to that port and force Windows to allow the file and print sharing?

That problem resembles the same situation when that port is blocked in the firewall.
Jim McLeod 0 Reputation points

2025-09-25T18:23:03.31+00:00

Was unable to successfully uninstall KB5065426 on my server - located and initiated an update removal, after reboot the update still shows up, Unable to initiate another update removal. Forced to perform workarounds to access my business data.

Will be installing Linux for evaluation, this is untenable.
Stephen Grimmer 0 Reputation points

2025-09-25T22:14:33.9533333+00:00

uninstalling this KB fixes event id event id 6167 when mapping a drive...
Aeris_Valetine 20 Reputation points

2025-09-26T07:29:32.7733333+00:00

When this updated on windows 11?
David 0 Reputation points

2025-10-08T09:35:32.4733333+00:00

I'm seeing more and more computers experiencing this problem. What's the solution?
GJ Eldering 0 Reputation points

2025-10-10T15:35:32.3833333+00:00

I'm also having trouble creating Linux shares in Windows 11.

I keep getting error: 0x80070043.

I've tried everything, unfortunately, without success.

Ping to Linux works fine, and from Linux, I see the share on Windows 11.

So, there's an error creating the shares from the Linux PC to Windows 11.

I hope Microsoft fixes this soon.
ahmad hazwan mohd adris 0 Reputation points

2025-10-15T01:35:48.36+00:00

any update from october 2025 can solve the issue. i need to reimage a lot of device from many site since the update cannot uninstall.
Susan E Bradley, CPA/CITP/CFF, GSEC 40 Reputation points

2025-10-15T03:55:49.16+00:00

https://www.askwoody.com/forums/topic/ms-defcon-4-finally-24h2/#post-2814835 See if the September updates help
James Imray 10 Reputation points

2025-10-30T02:04:48.78+00:00

I am no expert but I undestand the problem is with duplicate machine SIDs (not duplicate user IDs) which is why you are still having this problem. The machine SID is the user SID after the last "-" and any numbers after that are removed.

I check machine SIDs in Powershell with the command "Get-LocalUser | Select-Object Name,SID" (without quotes and ignore the SID result from the last dash onwards).

25 answers

Sidney Duffy 265 Reputation points

2025-09-11T10:52:08.7233333+00:00

I have performed additional tests using some machines which were cloned (thus having the same machine Security Identifier (machine SID)) with and without KB5065426 applied to Windows 11 24H2.

If KB5065426 is installed, then file or print sharing between any cloned computer with same machine Security Identifier (machine SID) - FAILS.

If KB5065426 is uninstalled, then file or print sharing between any cloned computer with same machine Security Identifier (machine SID) - WORKS.

If KB5065426 is installed, then file or print sharing between any computer which has different machine Security Identifier (machine SID) - WORKS.

So it seems clear that now after decades Microsoft has killed/blocked file sharing and printer sharing due the same machine SID.

Microsoft - wake up and fix this issue!!!!!!!!!!!!!!!!!!!!!!!!!!! or provide a way to disable the machine SID check
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18 people found this answer helpful.
Sidney Duffy 265 Reputation points

2025-09-11T08:16:12.7+00:00

It is great that Hendrik provided a "potential" solution, but as others have mentioned this does not actually solve the problem.

Likewise I found the ONLY way to make network sharing work again is to uninstall the KB5065426!!!

Having a patch from Microsoft which kills network sharing is extremely poor and will likely affect thousands of people who shre files at home or many SMB.

Microsoft - wake up and fix this issue!

Eugene Mollentze 55 Reputation points

2025-09-11T11:47:32.0133333+00:00

Thanks so much for this! at least the main issue has be found.

David Sivan 0 Reputation points

2025-09-11T13:38:31.0833333+00:00

I also checked it and while I did see on 1 client that has this issue that the two machines are cloned with same SID, I checked on another client that I know he has 3 computers that all of them are clones with the same SID and it works for him even after KB5065426 is installed.
so I am not 100% sure it's just a SID clone issue

Phillip Holybee 0 Reputation points

2025-09-11T16:03:02.0533333+00:00

Another oddity in my case and from what I have heard elsewhere, If 2 computers have the update, file and print sharing doesn't work, however if 1 computer has the update and the other does not, File and print sharing works. Seems in many (though maybe not all) cases, the issue is caused when both computers are updated. P.S. The computers I am working with are clones also.

Eugene Mollentze 55 Reputation points

2025-09-11T16:17:00.9233333+00:00

I will be trying to use 3rd party stuff tomorrow to see if i cna make the SID unique to the pc and taking it from there. Will let know as soon as i know

Sidney Duffy 265 Reputation points

2025-09-11T16:28:55.5966667+00:00

I found that to be the case as well, if one machine has KB5065426 and another does not then network shares still work irrespective of machine SID clone status. So sometimes if can depending on the rollout status of KB5065426 that the problem may start with one or two computers and then after others have been updated and rebooted, they too will fail.

Kevin OBrien 195 Reputation points

2025-09-12T15:51:28.3933333+00:00

Agreed that these are cloned machines. I don't have time as an IT manager to install Windows clean, all the apps and get the settings just right for every new installation. Especially now that I'm getting hammered with Windows 10 to 11 upgrades on pcs that don't support 11 I'm going crazy.

Going to look into changing the machine Security Identifier which is probably in the registry.

rLap 0 Reputation points

2025-09-13T10:34:23.8333333+00:00

I have 8 * WIN 11 pro , workgroup -not domain with identical SID and I can confirm the above post. Different SID - no Problem, Identical SID (due to cloning) + KB5065426 -->problem with net use and rdp logon.
I once read a blogpost of
of Mark Russinovich concerning of NOT necessity of different SID, we always cloned new machines with acronis backup, restore.

Chatgpt confirmed that the blogpost was from 2009 here:
Mark Russinovich (Sysinternals) hat tatsächlich vor vielen Jahren (2009!) in seinem Blog „NewSID Retirement and the Machine SID Duplication Myth“ geschrieben, dass doppelte Machine-SIDs in Windows keine Probleme verursachen.

DeBeq 0 Reputation points

2025-09-25T22:45:16.08+00:00

This was a great post. Saved me a ton of time. Thank you greatly!
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Sidney Duffy 265 Reputation points

2025-09-11T16:36:37.4133333+00:00
To validate that it is the machine SID which is the root cause of failed microsoft file sharing between PCs when both computers have KB5065426 installed, I conducted the following test.

I made two identical virtual machines which I confirmed had the same machine SID as my desktop.

The first virtual machine copy was used as the reference machine and would always refuse to connect to my desktop windows share (constantly asking for username & password).

The second virtual machine copy as one would expect also did not connect to my desktop windows share (constantly asking for username & password). But this is expected if the machine SID is the cause.

On the second virtual machine copy, I then use the tool SIDCHG to change the machine SID and allowed it to reboot.

On the second virtual machine copy, I checked and confirmed that the machine SID had been changed and was now different to the other VM and my desktop machine SID.

On the second virtual machine copy, I then attempted to connect to the network share on my desktop and it worked exactly as it should :)

So the only thing which changed in all of this was the machine SID of the second virtual machine copy.

Now that I had validated this hypothesis usign some virtual machines, I found another cloned PC with same machine SID which was exhibiting the same failure to connect to my desktop windows share (constantly asking for username & password). After changing the machine SID with SIDCHG on that computer and rebooting, it could then access the network share on my desktop without constantly asking for username & password time & time again.

Also be aware in some instances, I have also seen KB5065426 disable file & print sharing, so you may find sometimes this needs to be re-enabled.

In a few other test I have also noticed that after KB5065426 a network can inexplicably be changed from being private to public or vice versa.
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12 people found this answer helpful.
Axel Böswetter 15 Reputation points

2025-09-15T06:24:31.6766667+00:00

Thanks for testing/ narrowing down this issue so precisely. I had the same problems in our office with cloned machines and I was able to fix the issues using the SIDCHG Tool.

Little tutorial for everyone else:

If you want to check for similar SIDs, there is a Tool from Microsoft, called PsGetSid, that you can download here - PsTools. The Tool is inside the PsTools Archive. Just unpack the archive and call it on from cmd (command line).

So, running e.g. PsGetsid64.exe will output something like:

SID for \\COMPUTERNAME: S-1-5-21-294120173-2056661379-3573357989

If you verified that you have computers with the same SID, you can move forward using SIDCHG.

WARNING: AS CHANGING THE SID IS SOMETHING REALLY LOWLEVEL MAKE A BACKUP OF YOUR MACHINE BEFORE RUNNING SIDCHG WITH A TOOL OF YOUR CHOICE!

Just run (administrative command line):

sidchg64-3.0b.exe /KEY:%LicenseKey% /RMK

Replace %LicenseKey% with the current Trial license key from the SIDCHG website. They post a new key as image every month.

If you enter this command above, you sometimes need to reboot your machine first to stop some services that may run. SIDCHG will "say" that.

After reboot use the same command and proceed with "Y" - then you will be logged off automatically from your machine and the SID change will be executed. Please do not log in manually at that time - just wait! The machine will be shut down, if the process is finished.

Then just power on again, and as Sidney wrote, everything should work again.

Good luck everyone!

Bernard Wiid 5 Reputation points

2025-09-15T09:19:54.55+00:00

I can also confirm 8 identical machines
4 x POS units
4 x Backoffice Machines

When KB5065426 installed on pos u cant access share
When removed its working

All machince also have the same SID

Will be running SIDCHG to fix

Dont want to setup machine from scratch

Paul Verboom 0 Reputation points

2025-09-27T00:16:18.37+00:00

Thank you so much for providing your tutorial. To my great relief, I could fix the small business network I had just upgraded to Windows 11. Having the business owner upgrade everything to make it more reliable and then having them see everything stop working one machine at a time as Windows updated itself was not a good look.

I will provide some background as it may help others. In my situation, I used 4 identical refurbished computers that came with Windows 11 pre-installed. When I turned them on for the first time, Windows led me through the setup and activation process. In hindsight, the reseller must have prepared all these machines with the same image file. When I used the PsGetSid utility, they all indeed had the same SID.

I used the following command line with the SIDCHG utility to make the required change.

sidchgl64-3.0m.exe /KEY:78@5i-QwUJM-woQEE-Kv /S /OD

You must take the value after the /KEY: from their website because it changes each month. The key value does not include the percent symbols shown in the sample command formats provided.

I turned off the antivirus as instructed but missed the step on one machine. I was pleased to see the utility recognized by name; my non-Windows antivirus that was still running.

On new fast hardware, the process can take several minutes, so be patient. However, if you try to log in during the process, a warning screen will appear, displaying the current step being executed. The number doesn't update, but at least it is some feedback that things have not gone off in la-la-land.

I tried the lite version of the SIDCHG found on the website on a test machine, but that didn't work for me.

Because changing the SID changes the identity of the machine. Any Microsoft services and credentials used by them need to be set up again. I my case, that included the following;

OneDrive, log in to OneDrive, point it to the pre-existing folder normally the default everything should sync up again.

Microsoft Office applications licensed through Microsoft 365, this includes Outlook.

Account passwords used by Outlook Classic.

The SIDCHG website lists command-line switches and processes that should address these issues, but after having one successful update, I wasn't prepared to experiment further.

I first started seeing the problem on Sept 5th, and could find no information for the whole following week. If it weren't for the people on this form, I don't know what I would have done. And Microsoft's only contribution to this thread is standard boilerplate that doesn't even acknowledge the root cause, so well documented in this thread. Must say I am disheartened by their response. The fact they added another failure mode to the authentication without adding an appropriate error message — well, that takes the cake.

Jim Dunleavy 0 Reputation points

2025-10-24T10:29:46.6866667+00:00

Many thanks for that information, most of my sites use a server to hold the data but a few small ones use peer to peer sharing, it stopped working immediately that KB was installed, I ran your suggestion and it now works perfectly, I had previously uninstalled that update but it reinstalled a month later and could not be removed. I initiated a system restore but this failed and booted to a recovery screen where you had to choose to restart, guess what? Another MS update broke USB k/b and mouse connections on the recovery screen!! The customer had to buy a PS2 K/B to continue.
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Giulio Gaudio 55 Reputation points

2025-09-11T08:27:02.0133333+00:00

Same problem all the share in the local area network are lost, unable to connect to any share, this problem is caused by some windows updates named : KB5064081 and KB5065426, sometimes solved by removing it.

Microsoft - wake up and fix this issue!
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6 people found this answer helpful.
Mitchum English 0 Reputation points

2025-09-12T08:22:24.6366667+00:00

i have lost hours trying to fix this issue i uninstalled this idiotic Kb file none of my printers work, i have reinstalled drivers, i have logged in on a different profile to check and the same issue,,,, what a poor and sad story Microsoft.... still battling this out probably have to restore windows as DISM and sfc dont do anything either... pathetic

Austenite 0 Reputation points

2025-11-12T06:26:15.42+00:00

I was able to fix it today by using pressing the "Reinstall now" button in the "Fix problems using Windows Update entry, which is in Settings, System, Recovery.

Since KB5065426 had broken file and printer sharing, I had applied further updated and enabled 25H2, so uninstalling was not an option. It took a little while to download and install, and about half an hour of shutdown and reboot, but after that was back up and running with no obvious changes to any other behaviour.
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Hendrix-V 6,460 Reputation points Microsoft External Staff Moderator

2025-09-10T23:37:15.5833333+00:00
Hi Kevin OBrien,

Thank you for reaching out regarding the issues you experienced with file and print sharing after installing Windows Update KB5065426. We understand how critical this functionality is for your workflow, and we appreciate your patience.

FYI, the KB5065426 update introduced security enhancements that:

Reset some network profiles from Private to Public.

Disabled File and Printer Sharing and Network Discovery.

Blocked insecure guest logons by default for better protection.

As a result, even after re-enabling sharing settings, connections may fail if these new security requirements are not addressed. Removing KB5065426 restores functionality but also removes important security fixes.

Here a step-by-step guide to address the issue without removing the KB5065426 update, please kindly follow:

1 - Set Your Network to Private

Go to Settings → Network & Internet.

Select your active network and set it to Private.

2 - Turn On Sharing Features

Navigate to Settings → Network & Internet → Advanced Network Settings → Network and Sharing Center → Change Advanced Sharing Settings.

Enable:

Turn on network discovery

Turn on file and printer sharing

3 - Allow Guest Access (If needed)

For Windows Home:

Open Registry Editor and go to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters

Create a DWORD named AllowInsecureGuestAuth and set its value to 1.

4 - Check SMB Settings

If older devices require it, enable SMB 1.0/CIFS File Sharing Support:

Control Panel → Programs → Turn Windows features on or off.

5 - Restart All Devices

After applying these changes, restart both the sharing and client computers.

I look forward to receiving your update and I'm willing to collaborate with you till we resolve the issue. Please keep me informed.
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5 people found this answer helpful.
Stacy Russell 15 Reputation points

2025-09-11T20:20:51.2733333+00:00

What you suggest up there, the step by step? I had my IT out here and also Support what I thought was my Accounting Software glitch from 7 am until 3 pm when (and I thought this from the very beginning) we said, why not just uninstall it. We did everything you said up there multiple times and nothing worked but uninstalling that update.

Thomas Bunch 5 Reputation points

2025-09-11T21:57:39.4633333+00:00

tried that it still does not work I have several Location with this problem

Thomas Bunch 5 Reputation points

2025-09-11T21:58:25.96+00:00

can't uninstall update it is locked

Hendrix-V 6,460 Reputation points Microsoft External Staff Moderator

2025-09-12T04:42:26.8033333+00:00

Hello Kevin OBrien,

Just checking in to see if the above information was helpful. If you have any further updates on this issue, please feel free to post back. If the answer is helpful, please click "Accept Answer" and kindly upvote it. Accepting an answer helps us track the effectiveness of our support efforts.

Kevin OBrien 195 Reputation points

2025-09-12T15:54:18.86+00:00

These are the first steps I tried, although I will not use SMB 1.0 or guest accounts.

It appears to be an issue with matching SIDs from cloning computers.

Karen W 10 Reputation points

2025-09-12T18:32:11.0233333+00:00

I did every step (except guest access) and still it does not work. :(

олексий горбатько 85 Reputation points

2025-09-12T19:10:07.38+00:00

Check sid, the matter is repeat of sid of two copmuters

Bons Chan 0 Reputation points

2025-09-16T03:41:50.7033333+00:00

Thanks Hendrix-V, We have several sets of computers (LANs) that are affected by this. I tried it on the first set of computers on a LAN and it worked. But doing it on our other systems and it did not work.

Steve Taylor (Staff) 5 Reputation points

2025-09-16T09:36:02.1933333+00:00

We also have major issues with this update. It stops certain software being run from mapped drives and breaks some of our printers. The fixes you've suggested do not make any difference on our system and we don't have duplicated SIDs.

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Steve Gutteridge 10 Reputation points

2025-09-17T09:56:37.59+00:00

I have tried all of this and I still cannot connect to my Buffalo Linkstation HD-H240LAN NAS device, which only supports SMB1. This happens on both a Windows 10 machine (following update KB5065429) and a Windows 11 machine (following update KB5065426). In both cases, uninstalling the update fixes the problem.

Alexandru Iosif 0 Reputation points

2025-09-17T11:58:46.72+00:00

Had the same issue, only uninstalling the update worked

Michael Phillips 0 Reputation points

2025-09-17T21:39:53.27+00:00

This didn't resolve my inability to access 'WDMYCLOUD' devices

Lrac 0 Reputation points

2025-09-18T02:58:19.7533333+00:00

@Hendrix-V

We tested this on three domain-joined Windows 11 clients: two clients have the update KB5065426 installed, and one client does not.

The client without the update can access shared folders hosted on the two clients with the update installed.

The two clients with the update installed can access the shared folder on the client without the update.

However, the two clients with the update installed cannot access each other's shared folders.

When we ran Get-SmbClientConfiguration on the three clients:

The two clients with KB5065426 installed showed EnableInsecureGuestLogons : False.

The one client without the update showed EnableInsecureGuestLogons : True.

We changed EnableInsecureGuestLogons from False to True on the two clients with the update installed, then tested access to the shared folders.

The error persisted — the login credentials prompt still reported wrong password. We also tried on different domain users.

Lrac 0 Reputation points

2025-09-18T03:03:01.04+00:00

@Hendrix-V

Any feedback you can provide would be appreciated.

Hendrix-V 6,460 Reputation points Microsoft External Staff Moderator

2025-09-19T04:24:31.35+00:00

Hi Kevin OBrien,

Thank you for clarifying, that’s an important detail. If the issue persists even after restoring sharing settings and avoiding SMB 1.0 or guest accounts, and you suspect SID duplication from cloned systems, that points to a trust and authentication mismatch rather than just a network profile reset.

Here’s what you can do:

1 - Check for Duplicate SIDs

Use PsGetSid from Sysinternals:

PsGetsid.exe

Compare outputs across machines.

2 - Regenerate Unique SIDs

Run Sysprep on affected machines:

sysprep /generalize /oobe /shutdown

This resets the SID and prepares the system for a unique identity.

3 - Rejoin Workgroup or Domain

After SID regeneration, rejoin the machine to the workgroup or domain if applicable.

4 - Verify Sharing After Reset

Re-enable File and Printer Sharing and confirm the network is set to Private.

Please keep me informed on the issue.

Thanks!

Susan Bradley 56 Reputation points

2025-09-19T04:53:28.09+00:00

For the Buffalo NAS can you see if this helps? https://github.com/adricist/Buffalo-NAS-SMBv2-Patch

Gautam kumar 0 Reputation points

2025-09-19T05:01:12.2533333+00:00

I've completed all above steps but not resolved

Steve Gutteridge 10 Reputation points

2025-09-19T10:08:07.4733333+00:00

The Buffalo Link Station is an older model, HD-H240LAN, which is SMB1 only. (SMB1 has been enabled, and all of the above recommended steps taken). Same problem on both Windows 11 and Windows 10 (different update KB number), fixed in both cases only by rolling back the most recent update.

Jim McLeod 0 Reputation points

2025-09-20T18:55:42.4833333+00:00

I have two Windows 10 computers (not clones) that were individually updated from Windows 10 to Windows 11. I uninstalled the update and followed the steps given above, performed numerous cold boots. Access to shared files worked briefly yesterday but not today, files sent to the printer only printed after a computer cold boot.

Bob Sislow 0 Reputation points

2025-09-21T20:24:47.1266667+00:00

If you are on a Domain Network you CAN"T change your Network setting to Public or Private. The file sharing issue shows up in Domain networks as well. I HAVE NOT FOUND ANY WAY TO FIX IT OTHER THAN REMOVING THE SECURITY UPDATE.

Blair Stev 20 Reputation points

2025-09-22T00:15:32.8833333+00:00

Hi Hendrix- I’m on windows 11 pro and both machines on same lan network used to share files without any password needed. I had it off. I’ve already checked steps 1 to 3 in your comment above and I’m still getting the windows security asking for a pin or password and it won’t accept the right pin or password. This is so frustrating as we use QUICKBOOKS and it’s stored on 1 pc and I have to access that pcs PUBLIC folder which is shared and was working fine up until around 9/8/25. It seemed that update messed it up. Can you assist me in getting this resolved ? Any help is greatly appreciated!! Thank you.

I have another issue where it knocked out the SQL server agent and ACT program won’t load now. Happened around the same time 9/8/25. That’s on a home pc which my wife uses and we’re about to transfer over to the new act. Cant now.

Maurizio Ricciardi 0 Reputation points

2025-09-25T17:30:27.79+00:00

KB5065790 risolve

Robert Sandoval 0 Reputation points

2025-10-10T05:32:49.0133333+00:00

I have a few machines on a work group. my win 11 pro is used for all backups via sync for some active stuff and via back up on others. some can login to shared drives no problem, others can not. Checked the sids via psgetsid. they are different. The affected machines are win 10 pro. Yet some others work fine. if i use remote desktop it works for manually cutting and pasting but its been a lot of work reconfiguring the broke stuff and all the manual copying. Is there going to be a fix soon. or a work around that works? Anyone? What are the big company's doing?

Dana McCarthy 0 Reputation points

2025-10-22T18:35:59.1133333+00:00

This worked for me, as long as only 1 end of the connection had the update in place. Before doing this if the receiving end of the connection had the update installed, then the connection failed regardless. Now the connection works unless both machines in question have the update in place; in that case, the problems still exist.

WayneK 10 Reputation points

2025-10-28T13:08:16.5366667+00:00

The above solutions DO NOT WORK if the machines have identical SIDs. After the 24H2 update two working machines now fail SMB sharing and unless the SID of one is changed they will never work regardless of what anyone does. The vendor sent me two identical machines with cloned drives having identical SIDs. I now have to take one of them out of service, return it to the vendor to have it re-imaged or resort to some very destructive tools such as SIDCHG or sysprep that may destabilize it forever. Based on the amount of time I've lost due to Microsoft's wrecking ball I would have been better off simply replacing one of the machines and selling the one with the duplicated SID on eBay. MS provides a group policy work-around for the enterprise customer but it's left the rest of us "insignificant" customers with broken networking. This is proving to be a very costly error. If the objective was to increase SMB security MS certainly accomplished that goal: An SMB share that NO ONE CAN ACCESS is very secure.

Clif 5 Reputation points

2025-10-28T15:34:29.9133333+00:00

just do the windows updates again microsoft has fixed this issue. https://www.msn.com/en-us/news/other/major-windows-11-update-bugs-fixed-with-a-new-release/ar-AA1ORmtZ?ocid=msedgntp&pc=U531&cvid=68fa378b694346c796f34df3d93cc2a0&ei=29

WayneK 10 Reputation points

2025-10-28T16:45:41.5266667+00:00

No Microsoft have not fixed it. My affected machines have the '0773 kb and they still fail to share via SMB and still produce event log SMB errors related to duplicate SIDs.

This article, dated after the '0773 kb, admits the problem persists.

https://support.microsoft.com/en-us/topic/kerberos-and-ntlm-authentication-failures-due-to-duplicate-sids-76f7394d-c460-4882-9ed1-d27e0960f949

The only solution is for enterprise customers and I read this morning that someone contacting them for the group policy work-around linked to in the above claimed it didn't exist.
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Giulio Gaudio 55 Reputation points

2025-09-11T09:28:13.16+00:00

It seems the problem appears in maior cases with Cloned OS machines using Acronis or Macrium or similar software all the PC cloned has the same SID : Security Identifier (SID) is a unique, immutable identifier of a user account, user group, or other security principal in the Windows NT family of operating systems. so after 30 years Microsoft company blocked the file sharing and printer sharing due the same SID ???!!?!

Most companies clone operating system images to replicate them on hundreds of other machines distributed across multiple locations of the same company!!!!

Microsoft - wake up and fix this issue!!!!!!!!!!!!!!!!!!!!!!!!!!!
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3 people found this answer helpful.
Sidney Duffy 265 Reputation points

2025-09-11T10:00:52.3233333+00:00

This is supported by Mark Russinovich's blog article at https://v4.hkg1.meaqua.org/en-us/archive/blogs/markrussinovich/the-machine-sid-duplication-myth-and-why-sysprep-matters which indicates that SSID is were not exchanged between computers for network shares.

It would be good to know if others having these issues have had machines deployed / cloned using Acronis or Macrium etc.
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KB5065426 update stops file and print sharing from working

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