xp will not boot in normal or safe mode. goes to a black screen with no cursor. I've tried resetting cmos. xp cd starts and gets to the screen saying windows is starting and freezes. I have tested the hd with seagate diagnostics and all passed. right now spinrite is looking for errors on the drive. it's at 70% with no errors and three hours to go. I tried swapping out memory and checked for viruses with mcaffee's magic bullet. what have i forgotten?