Sometimes updates genuinely take 2-4 hours, especially major Windows updates. Sometimes updates do look frozen but are still processing in the background.
If it's more than 4 hrs. or say overnight, then try:
Hold the power button for 10 seconds until it shuts down completely
Wait 30 seconds with it fully off
Disconnect the power cable
Wait another 30 seconds
Reconnect power and turn it on
If the above fails then you have to boot into Safe mode > Windows Recovery Environment (WinRE):
Choose Troubleshoot → Advanced options → Startup Repair.
Troubleshoot → Advanced options → System Restore
Troubleshoot → Advanced options → Uninstall Updates → Uninstall Latest Update