Yeesh... That's the pits! Disable any overclocking features that
your motherboard may have. Sometimes it is a RAM problem.
If you have more than one stick of RAM, removing one can help.
If that fails to work try removing ~anything~ not essential to the
installation. Make your computer and plain as possible. Helps if
you have a PS/2 keyboard and mouse handy, too. The XP installation
process gave me much stress when after a while it decided to refused
input from my USB keyboard and mouse.