I recently installed a GTX 550 TI, and soon after I installed the drivers I lost all sound.
-enabling sound in bios (it was never turned off)
-Uninstalled all NVIDIA Drivers including display and sound, and just installed the display without the sound drivers
-Installed my LENOVO drivers that came with the pc
-Uninstalled the Realtek Audio drivers
-I used speakers/multiple headsets
Also, when I try to right click and test the speakers it tells me "Failed to play test tone"
I made a second partition and installed Windows 7 on there and the sound works just fine. If anyone could help that would be great.