Hi,
4 hours is an extremely long time for an update.
Are you running on an older computer, or booting from an HDD?
Was it a feature update? (Something like "Windows Upgrade 22H2" or similar name)
Are you maybe installing Windows 11?
If it is still making progress, I would leave it for a bit longer. Is the progress percentage changing?
If it doesn't complete in about 2 hours, you'll just have to restart it. It will probably figure it out, otherwise you may have to reinstall Windows.
Make sure you have a backup of your files right now, in case something goes wrong.
Sincerely,
LightJack