It might be wise to disable the onboard sound before installing the sound card, just incase there are any conflicts. It's very easy to do via the PCs Bios. Do you know how to do this? When your PC boots up, the first screen you see is black and white and displays your IDE hardware. When you see this, press the "Delete" key and your Bios will appear. There should be an area in there called "Integrated Peripherals" where you will find your onboard audio settings with an Enable / Disable option. Don't forget to save your settings before you exit.