"If I make a backup of my C drive does it format my C drive or just replaces the files?"
No, it does not format. Try choosing the backup wizzard. You are not obligated to do anything. Your options can be to back up all or some files. You can choose where to install the backup file,,,ie- to drive F. if you have a large hd.
What it does NOT backup is the hidden files. Maybe if you removed all hidden attributes (folder and files) it may copy those.
I backed up all my C:win2k files thinking I could just replace them if they got corrupted. NO GO.
GHOST if you can. Try whatever you attempted to back up by activating the backup utility to replace your target files. (to be certain that it did in fact back up what you think it did).
Perhaps someone more technical may correct/add to this.