Upgrading from win7 home premium to win 7 ultimate

[jamoskeag3]

I am going to upgrade from win7 home premium to win 7 ultimate. Since win 7 is already installed, I understand that everything is already installed on my PC, and really all i need to do is enter the product key to unlock the higher level features.
1`. Is this correct?
2. Can some one provide some detail on how this works, and perhaps provide a link to where this procedure is discussed. (I cant seem to find anything good when i searched.
Thanks in advance.
Jamos

[UncasMS]

=> start
=> all programs
=> Windows Anytime Upgrade
=> enter key

[jamoskeag3]

Thank you.
It worked real fine and install was simple.

[UncasMS]

good to hear