It is probably easiest to boot into windows. I don't know exactly how a console of grub works, but you should try to get pass a command like:
title windows
root (hd0,1)
chainloader +1
use (hd0,0) if windows is on hda1 and (hd0,1) if it's on hda2. You get the picture. Try different commands.
If that doesn't work get a knoppix cd and install a new boot loader. knoppix runs 'live' and doesn't effect your harddrive. You should always have a live cd in case you screw up your harddrive.
Good luck!
E