Originally posted by: Saltin
Place the 2k or XP CD (whichever) into your drive and allow it to boot from the CD.
Wait while it preps up, eventually you will get an option to repair (press R). It's right beside the install options.
Don't worry about not having an Emergency Repair Disk (ERD). Just let Windows try to fix itself. Choose automatic repair. It will fix the problem I reckon.