problems with the vista repair tool

Let me start off by saying i might have gotten a virus that changed the letter drive of my hard drives. Reason i think that is because when i try to do the repair install from the Install DVD my OS dosent show up that being said when it tells me to go look for the drivers then i go to my CPU my C and D drives are on the wrong letter. Could this be the reason i cant locate the OS to fix? Second question is, is there a way to change the letters around without being in windows itself. I cannot log into windows at all i just get the blue screen of death. Thanks if u have any input what so ever. Im just trying not to do a complete install i have way too may pictures to loose.I guess if needed ill have to get a new HD and start on that i guess.