Upgrade from Home Premium to Ultimate


Jul 20, 2006
Yea, I got Home Premium Upgrade Retail. Well, I'm thinking about giving it to my girlfriend and getting Vista Ultimate. My question is, if I upgrade from Home Premium to Ultimate, is the Home Premium key no longer good?

I don't want to go through the trouble of wiping my hard drive and reinstalling everything for Vista Ultimate.


Sep 8, 2006
This is one of those confusing topics. Legally, when you upgrade, the old license is no longer legal (an upgrade license simply gives you the right to transfer the old license to the newer version). However, I have never heard of anyone having problems actually installing the old license again. Some have said that MS doesn't lock out the old key due to rebuilds - where the old key has to be valid to upgrade it again.
Well, considering that you do not need the old product key to install the new one... and that you do not have to have Vista Home Premium installed to do the upgrade, I'd say go for it. Simply follow the instructions for a clean install of Ultimate.


Mar 21, 2009
Legally, you bought an upgrade license. This is not a full license so it is illegal to install the Home Edition on another computer at the same time that you have Ultimate installed. It is one or the other.

Also, you need to make sure that you understand your license agreement. If you had Vista Home Premium installed by the manufacturer, that is an OEM (Original Equipment Manufacturer) license. This means you CANNOT transfer that license to any other computer besides that one. Which means, even if it blows up and you still had the license key and disc, you cant install it on another machine. You must legally buy another copy of Windows.