I've had this problem a few times. I start with a freshly formatted harddrive - 60 gig. Get all my drivers and whatnot. Everything works fine with all my software installed etc... then after making about 10 backups(DVD Decryptor/Shrink method) my computer won't play DVDs anymore, in either DVD drive (one DVD R, the other no writing capability). So now I can no longer watch or write movies. I have no idea what the problem is, but formatting solves it. Please help, any ideas, I can't continue to format each time this problem occurs, but I like being able to backup DVDs.