Vc fez o backup (veja que eu consertei o erro) ?
Se fez faça o seguinte :
Retire essa parte (em negrito) :
# This is a divider, added to separate the menu items below from the Debian
# ones.
title Other operating systems:
root
title Ubuntu 7.10, kernel 2.6.22-14-generic
root (hd0,1)
kernel /boot/vmlinuz-2.6.22-14-generic root=UUID=90db8cd1-5fd9-4958-81cf-a7b28b98ee9e ro quiet splash
initrd /boot/initrd.img-2.6.22-14-generic
quiet
title Ubuntu 7.10, kernel 2.6.22-14-generic (recovery mode)
root (hd0,1)
kernel /boot/vmlinuz-2.6.22-14-generic root=UUID=90db8cd1-5fd9-4958-81cf-a7b28b98ee9e ro single
initrd /boot/initrd.img-2.6.22-14-generic
title Ubuntu 7.10, memtest86+
root (hd0,1)
kernel /boot/memtest86+.bin
quiet
e coloque essa no lugar :
# This entry automatically added by the Debian installer for a non-linux OS
# on /dev/hda1
title Microsoft Windows XP Professional
root (hd0,0)
savedefault
makeactive
chainloader +1