Anytime Upgrade using retail key

Hi,

I have Win 7 Home Premium (full retail version) installed and activated on my PC.
But then I purchase Windows 7 Ultimate (full retail version) as well.

Planning to upgrade the PC to Ultimate using Anytime Upgrade.
Concern is,
Does my Home Premium retail key will be obsoleted since it is "upgraded" ?

There is a sentence in the Windows Anytime Upgrade Window stating
"Make sure to enter your Windows Anytime Upgrade key and not the prouct ket that came with your computer or copy of Windows"
This is the one causing the concern.

Hardly any formal documentation on this, seems like a common FAQ but fail to find any solid answer.

Thanks!

kuman, welcome to the fourms! I have a question for you, your post is a little unclear. You stated that Home Premium is installed on your computer, and that you have purchased the full retail version of Ultimate. That being said, why do you want to upgrade using the Windows Anytime Upgrade? I was once going to do this, but was advised against it, as it's said to leave a lot of junk behind. A clean install is far better than a upgrade. And as far as your key goes, you have to have it in order to get the Anytime Upgrade. Since Microsoft is giving you a discounted price for the upgrade, I'm not sure if you can retain it or not. The other OS has to be in place when getting the upgrade. You may want to call Microsoft regarding whether your key is "obsoleted" when upgrading. Your Home Premium full version key is still good, as long as you remove it when installing a full version of Ultimate, meaning that you must format and install your full version of Ultimate. You may choose to install that version of Home Premium on another computer, if you want to. But doing an upgrade, I don't believe so, particularly with the Anytime Upgrade.