Checking out your system from Dell....
Drivers & Downloads | Dell US ... I see that that it only lists XP, 2000 and NT. Which tells me you'll be hard-pressed to find any drivers that will be compatible with windows 8 on that system.
In your picture you posted, you can clearly see that there is an issue with your video driver...I'm guessing it's with your onboard graphics.
I'm thinking it's time for a new graphics card, but keep in mind your PSU limations. If you get the latest and greatest GPU, your current PSU might not be able to power it.