Downgrading your Windows version can be a risky procedure with potential negative consequences, so it's important to think it through carefully before proceeding. However, if you do decide to downgrade to Windows 10 21H2, here's how you can do it:
1. Back up your important files and data to an external hard drive or USB storage device. This will ensure that your important data is safe in case something goes wrong during the downgrade process.
2. Make sure your system matches the minimum system requirements for Windows 10 21H2.
3. Go to the Settings app on your Windows system > Update & Security > Recovery.
4. Under "Go back to the previous version of Windows 10", click the "Get Started" button.
5. Follow the on-screen instructions to downgrade your Windows version.
6. Once the process is complete, you should be back on Windows 10 21H2. Make sure you check for updates to get the latest security patches and bug fixes.