You can try at least two things:
- Boot from Windows install CD--rescue mode, and enter "fixmbr". This should let you at least get back to Windows.
- Boot from any Linux "live CD"---eg Knoppix (also many of the more modern distros--including maybe your Fedora) If you can get into some form of Linux, open a terminal and type "fdisk -l" and post the output here
If you have valuable data on the disk which is not backed up, then proceed with caution---don't do anything that might write to the disk (fixmbr and fdisk -l are OK)