Problem with installing Virtual Server 2005

Hi, I tried to install Virtual Server 2005 on Windows XP service pack 3, but it says:
HKEY_LOCAL_MACHINEsoftwareClassesMsxml2.DOMDocument.4.0CLSID
Error 1402 Could not open key. Verify that you have sufficient access to that key.
I looked up in the registry and I have a full control in the registry. Have you ever experienced the same problem?
Any answer will be highly appreciated,
Thank you.
