change OEM product key to retail?

I have a Lenovo T61p with an OEM version of Vista Home Premium. I also have a
full retail version of Vista Ultimate. Should it be possible to use the
retail product key for Ultimate to upgrade the OEM version of Home Premium?
When I try this using the "Change product key" link in the System dialog, I
get an error saying I must either run Windows Vista setup (don't know where
that is) or enter a Home Premium key (which defeats the purpose). Thoughts?

t xjb

You cannot expect to upgrade from Vista Home to
Vista Ultimate by just changing the product key. You must
insert your Vista installation DVD into the DVD drive
and then upgrade to Vista Ultimate.

--
Carey Frisch
Microsoft MVP
Windows Desktop Experience -
Windows Vista Enthusiast

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"Dogleg John" <DoglegJohn@discussions.microsoft.com> wrote in message news:63CB5EC2-4A90-4786-8B49-45B570BB9062@microsoft.com...
I have a Lenovo T61p with an OEM version of Vista Home Premium. I also have a
full retail version of Vista Ultimate. Should it be possible to use the
retail product key for Ultimate to upgrade the OEM version of Home Premium?
When I try this using the "Change product key" link in the System dialog, I
get an error saying I must either run Windows Vista setup (don't know where
that is) or enter a Home Premium key (which defeats the purpose). Thoughts?

t xjb