I am running Windows XP Media Center Edition, with Realtek RTL8139/810x Family Fast Ethernet NIC as my sound card. My computer detects the device/driver and shows that everything's functioning properly, but no sound comes out - at all. I tried playing the system sounds but even those didn't work. All volume options are unmuted and on max. I have tried updating drivers, reinstalling, disabling/enabling, and I have no other sound drivers installed (except for the default Windows drivers). I've sent my computer off to TheTechGuys twice and they have not been able to fix it (the service is bloody horrible, I'd prefer to not have to send it out again; they've been trying to fix it for a month, which is ridiculous), so I'd really appreciate some advice. I really just want to know what the hell's wrong with this thing.