I have a gateway GT5662 with Vista home premium 32 bit os. I have no sound. I have an ATI Radeon HD 2400XT graphics A/V. When I check the dvice manager, its lists ATI HD Audio device, HD audio device & USB audio CODEC. All of them say they are working properly. The all 3 devices show the same 5 drivers listed. I tried Driver robot that said the were 3 drivers needed for these. when i downloaded & installed them, the one resulted in a gray screen that never went away. I had to shut down the PC to get rid of it. Any suggestions?