system restore doesnt take up that much space but sometimes with all of the computer killing things out there u cant get into windows at all to restore. ur best bet though costly, is to get another hard drive of the same size or at least bigger than the used portion of your current hard drive, then with norton you can create an exact replica of your hard drive the way it is and if any problems arise you can just boot form your ghosted drive and your back where you started no problems. thats just my opinion though i keep a dormant hard drive in my system just for that purpose and every once in a while i update my ghosted drive.