Ok, then you can use the FIXMBR command
Boot to the Windows XP CD and wait for it to give you some choices. Go into the Recovery Console. If your 'Administrator' account has a password, make sure you know it because you will need it to get in the console. Now then, just simply type in FIXMBR and accept the confirmation. After it is done, soft reboot
by typing exit
into the console (if that does not work, try typing shutdown -r
). If you hard reboot, you might damage the MBR again...
All you have to do then is make sure the disc is out of the DVD drive before it boots up. It should
boot correctly after this