Yes, while Microsoft thinks you will love all the features of Windows 10, you will have one month or 30 days after upgrading to revert back to the previous version of Windows on your device. To go back to the version of Windows from which you upgraded, please do the following:
- Go to Start >> Settings.
- Choose the Update & Security icon.
- Then go to the Recovery section and under "Go back to Windows 8.1" or "Go back to Windows 7," click "Get Started."
If you want to roll back more efficiently with all your programs and data you previously had, you will be better of creating a full backup before upgrading.
Windows will ask why you are going back, give you some warnings and then do its thing. It is relatively simple, although the process will take a while.