I'm not sure how solid it is, but I seem to recall that the latest versions of Partition Magic will create a partition on a drive, as long as it's defragged, even whilst there is data on it. It might be worth giving that a go, moving all your stuff over to the new partition and then reformat the old one?
edit : In my opinion, there is a high percentage likelihood that your registry is the cause of the problems so saving and restoring would probably be a bad thing. Possibly you could hunt down and save registry keys individially and re-install them that way, but it's a lengthy process
