Hi,
Install the version you bought and disable them.
Alternately, boot with the DVD to a clean system and install without
entering a Product Key. You will be able to choose any edition you please.
To keep it, you must add a valid Product Key for the version originally
selected and activate within 30 days, the keys are not interchangeable.
--
Best of Luck,
Rick Rogers, aka "Nutcase" - Microsoft MVP
Windows help -
www.rickrogers.org
My thoughts
http://rick-mvp.blogspot.com