You will have to boot with FC Medium, and boot into the Rescue Enviroment.
There you'll have to setup GRUB.
So you'll need to know with
how your hdd is setup.
Then you'll have to reinstall/or install grub into the MBR of you 1st HDD where I guess Windooze is
installed. After you've done that you will have the GRUB Bootloader that will give you the choice of which OS can boot.