Ok then, this is what I would try. I would download PING and run it on a working XP machine. When prompted go to a shell. I would then dd the boot sector of the good drive and save it to a network share (USB would be fine as well). Then I would run PING on the laptop and dd the working boot sector back.
Of course you could always get yourself a copy of Win2K boot disks (about 5 floppys) and use the command console from there. You can get boot disks here