Hey man,
GRUB can be a beast. You have a few options.
If you are just worried about windows for now, boot up to the windows 7 CD, go to a command console and use BCD to fix the master boot record.
if you want to get linux back up and running, you can just boot up to a live cd and issue the grub commands from there.
I would give you some links, but some anti-spamming features on the site require me to have 5+ posts to add links. I am really interested in the regex alex uses because no matter what I did I couldn't get around it.