Try some of these links...
http://www.google.com/search?hl=en&i...=Google+Search
This one seems like it has some good info...
http://aumha.org/win5/a/xpvm.php
Also it seems some recently installed nortons products may cause a problem....
http://service1.symantec.com/SUPPORT...256b82006dee3b
Hope one of those help.