I have a computer with an AMD 720 X3, a primary drive WD 640 AALS, a relatively recently added Samsung HD103SJ, and a HIS 4850. It worked fine with the new drive for a while, but now the computer often fails to load (gets stuck at the "Starting Windows" screen) so I have to insert the DVD to revert to a restore point. A few times I have also gotten a DOS-like screen indicating that the Samsung drive needs to check its file system and it reports no problems. Also if I look at My Computer, the Samsung drive sometimes doesn't appear in the drives section and after that I'm pretty certain that the computer will not get past the "Starting Windows" screen. So does this sound like an OS problem or a drive problem and does it call for a reinstall or should I check something else? Thanks.