Hi. I'm David, and I'm happy to help you.
Is your laptop still on the desktop (within Windows Update in settings), or is it already stuck on that "Restarting/Updating" screen that prevents you from using your computer?
Only if you are on the "Restarting/Updating" screen, see the status of the LED that indicates HD/SSD usage. If the LED is blinking, do not turn off the computer and wait to see if the system will restart and finish the procedure normally. If the LED is off and doesn't show any activity, the process has probably stalled.
If the procedure is stalled, hold down the computer's power button until it turns off. Wait a few seconds, and turn it on again.
See if Windows will proceed with the procedure. Then see if the system will start normally.
If you're still on your desktop, try clicking "Pause for 1 week" (Windows 11) or "Pause updates for 7 days" (Windows 10) in the Windows Update settings. This safely interrupts the stuck process. Wait a few seconds, then click "Resume updates". This often forces Windows to re-verify the files and jump straight to 100%.
Let me know what happened.
Feel free to ask any questions you may have.