Xljuan,
If you would like assistance, please follow the steps below:
Step 1 is to download and run the utility at this link http://go.microsoft.com/fwlink/?linkid=52012, then click the Windows tab, Copy to Clipboard, then paste the report into a response message in this thread.
Step 2 is to look for and tell us about the Certificate of Authenticity (COA) affixed to the computer, if any. 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?
4. DO NOT post the Product Key.
Not sure what to look for? Click here: http://www.microsoft.com/resources/howtotell/en/coa.mspx