I’m really not sure at all how to wipe our PC’s harddrive and reinstall Windows XP.
Its getting quite buggy and we want to wipe it clean and start all over again. Reinstalling Windows without wiping the harddrive still leaves a lot of crap we’d like to get rid of 
Assuming you’ve got a real Windows XP installation CD, it’s easy to wipe out the hard drive.
Just turn off the computer, put the CD in the drive and turn the PC back on. It’ll boot from the CD and one of the first choices is whether to reinstall, repair, or to reformat the hard drive. Choose reformat, and 100% of your old installation will be destroyed.
Note you won’t have this option if you start XP from your hard drive, then put the CD in and let it start the install from there.
Also, depending on when/how you bought your PC, you may not have a true Windows installation CD. You may have a manufacturer-specific “restore” CD that can put your system back to the original configuration, but only if the hard drive is NOT wiped out first.
That can lead to a Catch-22 where yuo’ve wiped the hard drive and then discover yuo can’t reinstall XP withthe disk you’ve got. If you’re not 100% sure, the best bet is to call tech support at Dell, or HP, or whatever brand it is and ask them specifically how you can do this given the exact part number on the CD(s) you have.
FTR, I was able to do a HD format and new install of XP Home with the “restoration” OS disc for an HP machine.
Ah, I think that’s what we may have. We’ve already reinstalled windows from it but we’ve not been able to wipe the other junk on the HD, there’s too much rubbish to selectively wipe, we’ve backed up our documents and are ready to format.