Disregard my last message - I just realized that you cannot disable your hard drive when you are currently using it (Everything else you can). If you can, Once you are satisfied that you have everything you want copied over to your new hard-drive and copied your personal files that you need onto a dvd/cd rom then format your c:\. Make sure in the bios on boot you choose your new hard-hard drive! I'd do that first to be honest and let your computer load. As long as everything is backed up then doesn't matter if something goes wrong, which it shouldn't.