New To Server 2011 - Add In Problem

Hi guys

I've just build a windows server 2011 (my first build) and everything was running smoothly, but trying to install add ins results

with a problem.

Does not matter what add in I try to install I get the same error message whether its from the client desktop or when RD in to the server and trying to install from there.

Please see attached picture.

Any help would be grateful.