first question - do you have the original XP disk? Also be sure you have EVERYTHING backed up before you do anything (including making sure you note which programs you have installed, etc. and their license keys handy) because if you do a repair with your disk it may not be able to repair it and may only prompt you to restore the machine to it's original - which would basically be reformatting and wiping the entire drive out and starting it over again like you just bought it
