That probably means swapped drive numbers. I'm hearing strange rumors that windows can't boot from anything but the first BIOS disk. Fortunately, GRUB has the answer to this; try this:
If you enter it into your grub.conf, you don't need the "boot" command.
map (hd0) (hd1)
map (hd1) (hd0)
Thanks guys it worked like a charm!
One more thing how can I make a boot grub floppy for emergency?
I'm not sure just off-hand, so if it doesn't work, see "info grub". I think you "dd bs=512 count=1 </usr/share/grub/i386-pc/stage1 >/dev/fd0" and "dd bs=512 seek=1 </usr/share/grub/i386-pc/stage2 >/dev/fd0". But like I said, I'm not completely sure.