Can't connect to local database in SQL Server (2008) Management Studio
It could be that he did the proper thing and revoked rights to the BUILTIN\ADMINISTRATORS group. However, the right thing to do is in fact causing you issues. I suggest you have him remote back in and grant your login SystemAdmin role rights if that is what you should have. He could also reinstate those same rights to the BUILTIN\ADMINISTRATORS group as well, but that is not recommended.