@bade302b after years in IT, I found its just easier to backup the important stuff as the operating system can always be installed and usually a fresh install is better. I admit it's annoying loosing programs and apps, but fresh can be better. I usually keep at least 1 copy of the OS backed up though. Decided if my windblows does die, I'm moving to Linux where I'm more at home and doesn't have all the added nonsense of Microsoft and it's spying powers. (Although blocked on my windblows). 

 @ebb00298 I did stop backing up all of Windows a while ago, having realised just what you said about reinstalling... but then I start thinking about the other stuff on the Windows drive, that I wouldn't have in a reinstall, so I go back to doing the backup. Sigh.