Is it XP? Now take a deep breath. Put your xp cd in the cdrom. Go into your Bios (del or F2 at boot) and make the cd the first boot device. Next restart your puter and boot from your xp cd and then do a windows and do a repair leaving the current os intact. Try that first. Let me know what happens.
Noli Nothis Permittere Te Terere!!
EVGA 680i, Dual EVGA 8800GT'S (650/950), 4 gigs OCZ DDR2 1066, Intel Q9450 at 3.8 Ghz, Koolance Water Cooled, Dual Plextor16x DL DVD+/-RW. Dual WD 250gb 16mb Cache Sata 3.0. 3DMark06 score = 19,168.