nitecris,
If you lost your XP Home Edition CD, you can get a replacement.
1. If the CD was made by or had the computer manufacturer's name on the CD, contact the manufacturer for a replacement.
2. If the CD was a genuine MS hologram CD and your Certificate of Authenticity reads "OEM Software" in black lettering, you can ask your systembuilder to order a replacement CD from Microsoft. Microsoft does not charge the systembuilder for the replacement, but the systembuilder is allowed to charge you to cover the administrative costs of processing the replacement request.
3. If #2 above but the systembuilder is no longer in business, MS will send you a replacement CD for a $30 fee. See this link: http://download.microsoft.com/download/b/a/b/babc90a1-b794-4a94-84f5-cbc37827ddca/end-user_media_replacement_form.pdf
See this link for more info: http://support.microsoft.com/default.aspx?kbid=326246