It sounds like you mean DirectX 11 - I am not aware of any specific "ActiveX 11" video plugins. If you are referring to DirectX 11, the only way you can use it will be within Windows 7. And, if you have Windows 7, you already have DX11 installed. If you are running Vista or XP, you will not be able to use DX11.
Oh, gotcha. Like for Windows Media Player 11. Nevermind my first post. Thanks Aastii!
Yeah...Google is your friend.