Originally Posted by
nkedel
Which version of Windows?
...
If 10, most of your Windows-level tweaks will back up to your Microsoft account if you use one. For app-level changes, you can manually back up and restore the c:/ProgramData and c:/Users/[you]/AppData directories but that doesn't cover registry-level changes.
I had a Windows 10 update that seemed to cause deteriorating performance. I was a little nervous to try it, but I went with the Windows repair feature -- can't remember the exact name, but the one that leaves all of your files, etc., untouched -- and it was remarkably pain free. I still had to reinstall non-Microsoft programs and tweak some settings, but it did a remarkable job of fixing the performance issues I'd previously encountered. (See my Travel Tech thread from a few months ago, where several posters thought I was on the verge of a hard-drive failure, didn't have enough RAM, etc.)