XPS 8500 Problme. How can I use my actual graphics card (AMD Radeon HD 7570) instead of the Intel HD Graphics 4000.

I have an my XPS 8500 plugged into my TV (As my monitor) via the HDMI port, I can't figure out how to switch it from Intel HD Graphics 4000 to the actual video card AMD Radeon HD 7570. Can someone help me figure this out? I have been doing this for a long time and the quality is pretty bad in some games that seem like I should be able to run very well.

At first I was getting the message that it was a "Standard VGA Adapter" and that problem took long enough to fix. I downloaded the drivers from the dell support site and it actually shows up as the AMD Radeon now, but I just can't get it to switch. When I run DXDIAG it still shows Intel HD Graphics 4000 as my display.