LeoAlpha,
It depends on whether you've got a Recovery CD/Partition from the manufacturer or whether you have the standard Windows XP HOME CD.
With the Recovery CD/Partition, simply place the Recovery CD in the CD-Rom, restart the computer, making sure that the BIOS is set to start from the CD-Rom before the hard drive, (or access the Recovery partition during the normal boot process) and all the reformat and recover options will be listed for you.
If you have the standard WinXP CD, then the link below should help you get it done:
Windows XP HOME Repair Install
http://www.windowsreinstall.com/winxphome/installxpcdrepair/indexfullpage.htm
Windows XP HOME Install
http://www.windowsreinstall.com/winxphome/installxpwindowsinstall/indexfullpage.htm
Hope this helps.
Grif
my xp home OS is truly messed up. I want to uninstall it and reinstall it from scratch. Or maybe even uninstall it and install XP pro instead. How do I go about doing this?
(it is the OS that came with my computer. IT is not an upgrade.)

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic