Computer keeps restoring on it's on?

[HelloK]

I have a Dell computer, Windows Vista. When I restart my computer, it keeps restoring itself back to the beginning, as it was when I first bought it. I had to make a new administrator account to get all of my files, which is located in the new account under c:/ users. I transferred the files back under my original account, but they keep getting deleted with every restart. I've had this problem for about 2 weeks now. How do I stop the computer from restoring itself after every restart? Also, doing a restore and undo restore doesn't help at all.