Yes, a system restore allowed us to use iTunes on our family computer when we weren't able to because we deleted a bunch of stuff (and somehow deleted a driver or something, XP is waaaaay too touchy about drivers). On my latest build, about 2 or 3 months ago, I set a restore point as soon as all my drivers were installed and all my hardware was working, that way if I ever completely screw my OS I can go back to the beginning, it's practically a clean install! :)