do a fresh install from the home CD ....... put it in and boot to it.
after it will ask for a previous version of windows........ put in Me disk, it checks, after will ask to replace home CD and go on its way with format and setup .............:happy:
You can do a repair install with an upgrade cd.
You can also do a fresh install and you very likely won't need a cd of a previous version. Boot to the cd, the upgrade cd will search for a previous version of Windows and will detect your installation of XP on your harddrive. You can then go on and format the drive and install XP.