You need to go back to the steam app and right mouse click on the Game Guru Icon.
Choose properties, then the beta tab.
Choose the live version, not the public preview.
Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz, 2400 Mhz, 4 Core(s), 4 Logical Processor(s), 8gb RAM, Nvidia gtx660, Windows 7 Pro 64bit, Screen resolution 1680 x 1050.