Some apps need to be uninstalled Windows Update error
1] Find incompatible programs
Sometimes Windows will point out programs which are not compatible with the next version. If yes, then simply click on Uninstall and continue, and the process will progress as expected. If you need additional inputs, Microsoft has this official site Ready for Windows which can help you figure out which software versions are compatible with Windows 11/10. Select Windows 11/10 version, type in your App name, and you will get results about its compatibility. You can now easily figure out which software is creating a problem, and if there is an updated version which may work.
2] Uninstalled program, but the problem persists
If you did all the hard work to figure out programs which were causing the problem, you could try third-party uninstaller like Revo Uninstaller to remove the last traces of that program. The chances are that during uninstallation, those programs have left their traces, and registry entries. This will remove all of those traces.
3] Perform Windows Update in Clean Boot State
If that does not help, boot into Clean Boot State and run Windows Update.
4] Create a new user account
This trick has high chance of it resolving this issue. Create a new admin account on your PC, and initiate the setup. Since there are no third party applications installed on the PC for that user, it should go ahead. In case you have installed programs for that person as well, just uninstall all of them, and re-run the setup program.
5] Clean Install Windows 11/10
If nothing is working, this is your last resort. You can clean install Windows 10, and then post installation, install all the software you were using earlier. Just make sure they do work on Windows else use compatibility option for those programs. Lastly, make sure you have taken a backup of all the files before installing a fresh copy of Windows 11/10. Related read: Uninstall this app now because it isn’t compatible with Windows.