I have a version of Windows XP Professional 1 - 2 cpu (2002) that I cannot install because the product key information is lost. I do have the Label for the Certificate of autheniticity with code 00045-137-832-502 on it. My computer does not accept this code. What do I need to continue with installation? Should there be a 25 product key too with this CD? This CD was given to me as it had never been used or installed and I would like to use it to upgrade my computer's operating system. Any information is appreciated.