How to get rid of Windows 11 (and roll back to Windows 10)
So, you’ve installed Windows 11, kicked the proverbial tires and taken it for spin — and now you want to go back to tried and trusty Windows 10 until the new-OS dust settles. Can you uninstall it without having to reinstall your old operating system from scratch?
The answer depends on how long ago you installed Windows 11 and how you did so.
Let’s assume first that you didn’t use the Insider program to get Windows 11. (And you didn’t adjust your registry to manually go around any hardware block.) Instead, you were offered the upgrade because your PC had the right processor, TPM chip, and other necessary items. If so, and it’s not been more than 10 days since you installed Windows 11, you can go to Settings>System>Recovery and choose “Go Back.” This will revert your computer to the Windows 10 version you had before installing Windows 11. You’ll be asked if you want to check first for updates to Windows 11; decline that and follow the wizard to return to Windows 10.
Source: Operating Systems