your difficulties could be caused by confusion in the BIOS. Usually the BIOS needs to be told that its on board sound chip is not required - you've got a sound card instead. Reboot your computer and go into the BIOS setup, press delete or F1 while rebooting, which should be enough to go into the BIOS setup screen. Find the section that deals with onboard chips and disable onboard sound. save your changes and reboot into your operating system and see what you get.