dual-boot with Fedora

Fedora changes the MBR so that the XP install CD barfs

to get the XP install CD to work, need to boot into linux with a
linux rescue CD, then DON'T mount the hard drive, then zero out the
MBR like this:

dd if=/dev/zero of=/dev/hda bs=512 count=1

Then reboot with the XP install CD and install XP.

Save the mbr with

dd if=/dev/hda of=/boot/mbr.img bs=512 count=1

It can then be restored with:

dd if=/boot/mbr.img of=/dev/hda bs=512 count=1

or if you do not want/need to overwrite the partition table with:

dd if=/boot/mbr.img of=/dev/hda bs=446 count=1

as the partition table is kept in the last 66 bytes of the MBR.