Possible solution:
One method I have found that works is to pull out the non-essential cards from your system (except your graphics card). Remove your Sound, Modem and Ethernet cards. It is usually one of these cards that hangs the installer. Once you've completed the Windows XP installation, power down and add the cards back to your system one at a time. The reason you need to add these back one at a time is because Windows will recognize these cards as new hardware.