This solution is for an older version of Linux, but the same concept should translate to the same method that can be applied to newer versions as well.
However, from my understanding, it may have been possible that the Master Boot Record has been overwritten or corrupted in some kind of way.
If you have the ability to do so, first attempt to try and restore the MBR through Linux.
However, this could possibly be easily fixed by using >sfdisk
sfdisk /dev/sda -i -c 1 07
You may also want to use TestDisk to detect any issues
For Fedora specifically the following steps may help.
With Fedora CD Boot your computer with the first CD of Fedora in your CD drive (You have to enable your PC to boot from the cdrom, which you can set in the BIOS settings). At the installation boot prompt that you get, enter the following command:
boot: linux rescue
Press Enter. The installer will ask you a few questions like the language you would like to use, the type of keyboard etc. Then, if you have linux previously installed on your machine, the Fedora installer will automatically detect it and mount it in the /mnt/sysimage directory. Once the linux partition is mounted, you are dropped into the command shell prompt. The next step is to make your newly mounted directory the root (or parent) directory. This you do by running the chroot command as follows:
# chroot /mnt/sysimage
# _
Make sure to restore GRUB:
# grub-install /dev/hda