Oh I make a mirror image of the fully installed Win7 with all updates just in case something happens.
I don't bother with that, because if something messes up I just do another clean install. It only takes me about 3 hours to do one, AND install all my programs [including all updates, but NOT including zeroing out the disc].
I keep all my documents, pictures, and things of that nature on a seperate drive, and just link to them. THAT drive I keep a backup of, but I do it manually on an external drive. That way all I have to do is reformat my C:\ drive if something messes up [which it never has yet]. This is just the way I like to do things. I would NEVER do a repair on my operating system. I wouldn't be able to sleep at night knowing it messed up at one time or another.....LOL