Or you can DLoad
This .iso to make a bootable Recovery Console...
This will NOT re-install XP but it will enable some repair work to be tried from the Recovery Console...
Using Nero or another burning program burn it to CD making sure to check the option to create a bootable CD.
Boot to the CD...let it finish loading.
You will be at a command prompt window.
At the prompt type in fixboot and hit Enter.
Remove the CD and re-boot.
If no joy-joy repeat the above procedure except type in fixmbr and hit Enter.
Again remove the CD and re-boot.
A full list of all the RC commands is located
Here...Don't try any commands you are unfamiliar with...you've been warned.
Good Luck.