[cranshinibon]

what mobo are you using...also try booting up with each hard drive separately. ive had the same problem with my mobo when trying to boot up sata and ide using the sata as a slave.otherwise it could be a software issue...i agree however...dust can be an issue as well but doubtful. after making sure things are seated and neither of them boot up properly grab a windows live boot cd or an ubuntu live cd and grab an external and back up all the crap you absolutely need then kill disk it. after that reformat completely....ive had this sort of thing happen on my laptop and its a pain in the ass