Hello, I need help in fixing a computer running windows xp pro. the computer was running fine till 2 days ago when it stopped booting. Computer starts up, bots to xp screen then restarts I have tried all safe boot options, none work. all fail at mup.sys I have tried using xp disk to do a repair, and here's the fun part. The hard disk does not show up as C: in map command but is shown as the following: ? 2000mb ? 480000mb D: cdrom E: dvdrom I have install the hard drive on another system by usb and ran disk checker on and the disk seems to be ok, can access all files on disk. why is the disk showing as ? , I have tried the hard drive on a different IDE channel with the same results , is the hard drive showing up as ? the reason it wont boot?? Thanks