I had installed Windows 8 with a product key that wasn't matching my agreement and I needed to change it before activation, as I was sitting at an annoying "Activate Windows" message. I naturally went to the properties of the computer and didn't find any mechanism to change the key, only a repeatedly failed activation process.
I then found a support article that indicates that the "Change Product Key" link is not displayed if Windows is not activated
, which appeared to be my exact problem.
Here is the article:
Thankfully there was a resolution. I open a command prompt and entered:
"slui.exe 0x3", which popped up the activation key entry screen.
The article also notes you could do this from the search screen as well.
Now I am legally using my Windows 8 ultra-book.