bassicly go into your bios and set your comp to boot from the cd drive first,, then pop your xp disc (assuming thats what your using) into the drive and restart the comp,, when it prompts hit any key to go into the boot secting of the disc,, then theres a few menus , i think you need to go to setup xp,, then delete the partition and recreate it, then you can format it,,,