Windows\system32\config\system

please could u help?
my pc keeps coming up with the a problem every time i try and boot up.
it says the above file is missing and i can attempt to repair by starting windows setup with the original setup disc.
when i put the disc in and press r like stated nothing happens apart from the same message coming up. Ive also tried another windows setup disc which the same happened.
i cant seem to erase the harddrive through the start up menu aswell
my motherboard is a jetway v600da/dap
and it windows xp pro service pack 2

any ideas would be helpfull
thank you
Christopher Mullen
cmullen666@hotmail.com