Ok, first, DO NOT reformat before trying any of the mentioned ideas. That being said, Try to get your hands on a Windows 7 disc (any version should do. I have a Win 7 Pro disc, that I could loan you, just PM me your info, if you can't find a copy nearby) and use the repair function after booting from it.
Also, look into the Ubuntu Linux option, as well. You may have to use a friend's computer with a DVD burner, to make a copy of the disc image onto a writable CD/DVD, but Ubuntu is totally free, and it's the hot new thing in Linux. It's supposed to be very user-friendly. It has a slightly different interface from Windows, but it should get you through.
Here's hoping you can get your issue solved as soon as possible, with as little loss of data as possible, as well. *crosses his fingers, prays, chants,
does a rain dance, etc.*
Afterwards, MAKE A BACKUP of everything on your computer, as well, and store it in a safe place, in case something should go wrong, again, Heaven forbid. I can't stress the backup enough. BACKUP, BACKUP, BACKUP!