Hello.
If you are past the 10-day rollback window, you will need to do a clean install of Windows 7. You will also need to back up your personal files and reinstall any applications you want to keep.
If you don’t have a copy of Windows 7 installation media or a valid product key, you will have to purchase one from a reputable source. You can also try to contact your PC manufacturer and see if they can provide you with a recovery disc or a way to restore your PC to its factory settings with Windows 7. However, this may not be possible for some models or brands.
I hope this helps you to go back to Windows 7. Please note that Windows 7 support ended on January 14, 2020, which means that you will not receive any security updates or technical assistance from Microsoft. You may also encounter compatibility issues with some newer hardware and software. So, I don't recommend you to go back to Win7.。
Best Regards,
Hania Lian