Recently installed Windows 7 Home and since doing so the microphone on my USB Plantronics headset isn't working, but I can hear sound through the headset. I have tried uninstalling and reinstalling the drivers for my sound card (Sound Blaster model # 0460). With and without the drivers installed my computer is recognizing the headset and I can hear sound, but no working microphone. My computer is a Dell XPS 720. Any help would be appreciated.