I bought a PC with Windows 7 Home Premium , and realTek sound card. Everything has been working well, including sound, until I tried using my USB headset.
On plugging in the headset, I rightclicked on the taskbar settings , and disabled the RealTek soundcard, and made the Headset the default communications and audio device.
However, when I tried re-enabling the soundcard, and made it default, graphically, it shows that the sound card is in use , but no sound comes out of it. My speakers work well on another PC, and when I insert my USB headset and switch the settings, the headset works fine.