Click on “Start”.
“All programs” > “Accessories”.
If you don’t have the “System Protection” turned off, some options will appear there, with versions of Windows with different restore points (click on “Show more restore points”).
Now select a restore point and click on the “Next” button.
Be careful, once you have clicked that “Next” button, there is no way back to your current version of Windows.
The process of restoring your Windows to an older version (like the one from a month ago) is great in case that your operating system gets a nasty virus that you can’t get rid of, or it just gets too damaged and it’s impossible to repair it.
Notice that if you turn your “System Protection” off, you will save quite a lot of disk space that would get occupied by the old Windows restore points. But obviously, you won’t be able to make any restoration for your operating system.
The same system restore process works as well for Windows 8 and Windows 8.1.