I am running windows 10. When I hook up to my television via HDMI, the computer sees the TV set as stereo (Which it has for on-board speakers). The TG set (an LG 49UH6030) is hookup up to a surround sound amp (A Devon AVR 1640) via an optical cable. The Windows 19 computer only lets me select the output as stereo. Normally I get 5.1 surround from the TV. How do I get windows to output the 5.1 to the TV via the HDMI?