Wierd, you probably just confused grub, you can try typing in the commands manually if you're familiar with grub, tab completes commands and shows you options as long as you're on the right track, there's also a help command.
You may want to try re-installing grub and seeing if that brings it back, that's probably the easiest thing to do, just pop in your FC disk an type linux rescue at the prompt, follow along, you don't need network for this, when you get to a command line type
grub-install --recheck /dev/hd? <-- You need the recheck option since you've made changes and you'll have to adjust the device name to whatever drive you're using /dev/hda would be the first IDE hard drive, if you use Sata /dev/sda would be the first Sata drive.
Then type exit twice and it should reboot and hopefully be back to normal.
If not getting into windows should just be a matter of typing these at the grub command prompt:
root (hd0,0) <-- assuming Win is on the first partition of the first disk.
You may also want to DL this just to have around: