From what you've already stated, you have the Windows and KSS install CDs, correct? And you have already tried re-installing KSS? Have you tried re-installing Windows (and then KSS) from scratch?
"Checked the hard drive" -- how? What tests did you do?
"Swapped some boards" -- what boards? Where? Moving boards into the wrong slots on the motherboard is a good way to break the robot.
Have you tried plugging in a keyboard and booting the robot to Windows only? (by holding down SHIFT during the Windows boot sequence)