missing or corrupt C:\windows\system32\config\system ?

I have a foxconn MB running XP. The computer was running fine for years, then all of a sudden it won’t start up and I get this error:

Windows could not start because the following file is missing or corrupt
C:\windows\system32\config\system

I have placed the xp cd in the rom and tried to reboot from cd and it won’t. I tried to enter the repair screen and it won’t. I went into the BIOS and selected the cd rom drive as the only start up source. F12 won’t work. F8 won’t work. No matter what way I try to get this POS to load from the start up disk it will not do it. Does anyone have a workaround?