Unable to Select Objects and other stuffs,

Hi, like in the title recently i have installed some program and is impossible select from the viewport anything,
the only thing that you can select is the red cube, for the rest, usually to unselect, enough press in an empty space on the map, I can not even with UT2004

Can not select surfaces, objects etc. someone can help me out '? this happne with UDK , Unreal2004 not with U4

thanks alot if someone want to help me