how do i wipe a hard drive so i can instal a copy of windows xp home addition

what's on the partition now? windows will ask you if you want to format a partition of the hard drive during install

XP will format (wipe) the drive during the install process.

If you have an upgrade version of XP it will detect your old windows & overwrite it.

If you want to wipe the whole drive & install a full version XP onto a single partition just boot the XP CD & follow the prompts.

You will also be able to setup multiple partitions if you so desire.

This is a very good guide to all your options with installing/ reinstalling XP:

http://michaelstevenstech.com/index.html

Let us know if we can help further.