Been evaluating Win 8 for about a week now. With Stardocks Start8, it becomes quite useful. Browsing in Control panel, I find an entry for "Add features to Windows 8." This opens a screen where you have two choices - need key to activate, or already activated. When the latter is selected, another screen asks for a key. It will not accept the key used to activate Windows 8 Pro. I then searched the web and found this Microsoft explanation: http://windows.microsoft.com/en-US/windows-8/add-features-frequently-asked-questions Apparently, this replaces "Anytime Upgrade." And a separate key is required. My question is, what benefit will this provide and why is the explanation so nebulous?