I installed FC3 on a WinXP-sp2 system, whose c: drive was NOT being used (for real), or so I thought. And gave the entire drive, hda, to FC3. I reasoned that since my winXP booted into drive E:, the second drive, hdb, Grub would have no issues with booting Windows. However, although it boots FC3 nicely, when I elect to boot xp, it displays 'rootnoverify (hd1,0) chainloader +1' and stops.
What normally happens when you install Windows into a drive other than C: is that it puts virtually everything where you asked it to, except for its bootloader, which it puts on C:
So you've probably trashed its bootloader. You'll probably need to create a (small) partition on the first drive that Windows can write to (i.e. FAT or NTFS), make it bootable, and use the XP recovery console to reinstall the bootloader into that partition. As for your FC3 install, I'd re-do it once Windows is happy.
Wait for other suggestions too though; this isn't something I've attempted and others may have better ideas.
Paul.