I don't know why the driver didn't install correctly but here's a few more things you can look at and try 1. Open Control Panel->Add Remove Programs. Look for an entry for the Soundmax driver. Uninstall it. Once Soundmax is uninstalled you should see the Multimedia Audio Controller in Device Manager again. 2. Let Windows find and install the Soundmax driver this time. Open Device Manager, rt click the Multimedia Audio Controller. Select Update Driver. Follow the prompts to allow Windows to search for software and install it You can also see this guide from Microsoft http://windows.microsoft.com/en-us/windows/help/no-sound-in-windows Hope this might help as i think i'm otherwise stumped and out of ideas