Lexx,
Please follow these steps for assistance:
Step 1 is to run the utility at this link http://go.microsoft.com/fwlink/?linkid=52012, then click the Windows tab, click the Copy button, then paste the report into a fresh thread in the "Problems" section at this link: http://forums.microsoft.com/Genuine/ShowForum.aspx?ForumID=442&SiteID=25. The secton of the forum you are in now is for comments and other feedback.
Be sure to copy-paste your description of the problem as well.
Step 2 is to look on the computer or with the materials you received with the computer or with Windows to see if you have a Certificate of Authenticty (COA). If you have one, tell us about the COA. Tell us:
1. What edition of Windows XP is it for, Home, Pro, or Media Center?
2. Does it read "OEM Software" or "OEM Product" in black lettering?
3. Or, does it have the computer manufacturer's name in black lettering? EDIT: Oops disregard this>>In your case we would expect it to read, "Dell."
4. DO NOT post the Product Key.
Not sure what to look for? See this page for reference: http://www.microsoft.com/resources/howtotell/en/coa.mspx