Okay, when you go into the 'Licenses/Expansions' screen from the main menu, is AS displayed and not taking the code, or is AS missing from the list?
If AS is missing, that means that the installer placed AS in a different place from the AI Wars game and you need to re-install it giving it the correct path.
If AS is present and the license code is not taking, try typing the code out rather then copy pasting it in. There have been issues in the past with 'invisible' characters being copied when that happens.
If the code still does not work you will have to wait for someone at Arcen games to look at this as I can't help with that.
Hope this works for you.
D.