Vista - re-install upgrade to Ultimate from Vista Business

When I try to use my upgrade license for Vista Ultimate from my Digital
Locker account everything goes well until I am prompted to insert my Vista
disk. The upgrade starts the process and after I click install I get an error
message "Windows setup experienced an unexpected error. To install Windows,
restart the installation. Error code:0Xo" I try to start the process again
and it always come up with the same error message. Does anyone have any
suggestions. This is also a clean install that has all of the updates already
installed.
Thanks Hauki