...and that's why I pop a System Restore point every time, and right before, I install an update to a major app, or OS updates, or video card updates. Same with Time Machine on a Mac.

Doing this has saved me so much grief so many times... Oh, things went sideways? System Restore! Windows Update irrevocably b0rked the nvidia drivers? System Restore (and find out why)! {you name it}? System Restore!