This would be the easiest way to revert:
Boot up in Windows 10, go to the start menu then select settings. Click on the update and security icon and then select recovery.
You should see a “Go back to Windows 7” or “Go back to Windows 8.1” option. Click the Get started button to get rid of your Windows 10 install and restore your previous Windows install. Microsoft will ask you why you want to go back.
If it’s been over a month — or if you’ve run the Disk cleanup tool and removed the “Previous Windows installations” files or deleted the C:\Windows.old folder by hand — you’ll no longer see this option. Windows 10 appears to automatically remove the old Windows installation files after a month to free up space.