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i had the same problem...when i installed the drivers for the soundcard after a clean install of windows 7 , the OS loaded drivers on its own. But when i installed the vista drivers for the card via manual install, the sound died out a while later while i was gaming. When i uninstalled it, after the reboot the sound was back to normal. Uninstall the drivers from Windows7 and allow the OS to detect and install the hardware.