Confused Person - Need Major help w/ Video Card

[hayzee]

First, I currently have a compaq presario, s4100nx
Windows XP
768 ram
I believe my processor is an Intel Celeron w/ 2.5 ghz

I need to upgrade my video card, but in opening up my computer, I only have PCI slots...
So, I also check online w/ compaq & it tells me I have the following:
Total expansion slots: Three PCI
Available slots: Two PCI
Video graphics (AGP): 845GL

What does this mean? It says I have PCI slots...but that my video card is AGP? Is that right? I am SOOO confused! I have no idea what I'm doing.

So, essentially, I need someone to explain to me what that means and what kind of cards I can run....
Specifically, I want to know if I can run any ATI Radeon cards (will a 9xxx series work?) or Nvidia gfocre cards (6/7xxx series work?) on my pc.....
thnx for any help...

[Dilbert]

It means that your onboard video card (the one that came with the motherboard/cpu) is a AGP. No, you can't access it. But you can buy a PCI video card.

[GX1_Man]

You can run it IF your tiny Compaq power supply can run it. Anything over a FX5200 is suspect, and that might not work well either.

Check the specs at the Compaq website for that power supply. I'll bet it's 250-300 watt only, and you can't just go get a bigger one at CompUSA. They tend not to fit!

[dl65]

Just looked up that pc...... it looks like it came with a 200 watt power supply.

http://hardware.gamespot.com/Compaq-Presario-S4100NX-3285-S-1-2

dl65