Can video card be updated on my Dell Dimension 4550?

I have a Dell Dimension 4550. I have done many updates to it. I have a second hard drive with tons and tons of space and 1 gig of ram. Right now I am using a Radeon 9800 video card. I have noticed that a lot of computer games coming out are required a higher end video card than the one I have? Being that even though I have tons of space left on my newer system am I able to update the video card any more than that? I just do not really want to buy a new computer when I have done so much to this one.|||Yes, if you have an available slot on the motherboard, or you remove the existing video card, you can upgrade to a new video card.|||Yes, it can take an AGP 4X/8X Video Card. But beware, there are different chipsets and makers out there and prices vary widely. Research based upon what you do like games, applications, or making videos and DVDs.