My old computer's MB went out. By the time I would have payed someone to check and replace the board it was just as cheap to buy another box. Unfortunately it has Vista. Can't stand it!!!!!!!!!! Installed the old HD in new machine but cannot get it to boot. System tries but reverts back to Vista. What do I have to do to get this thing to boot off the second drive(XP). Any help is much appreciated!!!!!!!!!!!!!!