When I bought the computer, it came with Win 7 Home Premium - I replaced that with a retail version of Win7 Ultimate. If you want the problem fixed, the first thing to do is to replace those drivers with those you get from Dell and nowhere else. That's a red flag because it's a very good way to end up with a problem like you have. But you said ' I reinstalled the drivers,etc that came with the computer, then Windows updated some of those'. If it's not the drivers for the sound card, it's going to be hardware.
