dd if=/dev/sda of=/root/mbr.img bs=512 count=1
check it using file /root/mbr.img
restore
dd of=/dev/sda if=/root/mbr.img bs=512 count=1
file -s /dev/sda
should show the partition table
file -ks /dev/sda
shows if lilo is installed
or reinstall grub and auto find
mkdir /junk
mount -t -auto /dev/sdXy /junk
replace Xy with your drive letters
chroot /junk
grub-install /dev/sda
utilities for winxp
hdhacker
mbrwizard