What are your system's full specs? And does your system have an AGP slot, or only PCI (entirely possible if you have an older system, particularly if it's an OEM machine)? 

I had the same PC. You have pci slots. You can always get your system specs from the Dell site based on entering your service tag # from the sticker on your computer. It would also outline this in your docs you got with the pc. Dell has them in pdf if you misplaced them.

Now, the fun part. If you shop around you can get a pci video card that will work. I had a geforce FX5200 that was < $100 a year ago. I was running GC2 with 1GB of ram and the fx5200 (with 256MB on it - it was made by BFG) without issue. I since upgraded to a new pc before I tried Dark Avatar so I cannot attest to whether it would work.

If you can afford it, I would recommend you boost the ram also. I moved mine from 512 MB to 1 gigabyte before I bought the new pc and it made a big difference.

Here is a modern PCI video card. A PCI version of the radeon x1300.

WWW Link

Still though don't expect any miracles, this is still a relativly slow graphics card and you would probably just be better off saving your money for a whole new computer!

The Infamous Reno,

I run an Intel Celeron 2.4 Ghz processor, 1024 mb RAM, 160 gig 7200 rpm hard drive, and a PCI GeForce FX 5500 (256mb DDR) graphics card from 3D Fuzion. Kryo mentioned the GeForce FX 5500 above. I also keep my virtual memory cranked up. I keep most of the graphics set to fairly high quality with most of the textures active. Currently, I'm playing the unmodded new DA release on a gigantic map with 9 opponents, common planets, and the AI cranked up to the highest setting. The slowdown is not to bad at all, and is actually less than I experienced running DL unmodded on the highest settings.

The card was $60 at Comp USA amonth ago. It installed very easy, but I actually followed the instructions this time.

Most of my time spent with DL was spent on the same system with an antiquitated GeForce4 MX 4000 (128 mb) card. It is less than $30, but DON'T get this card or anything equivelent. It was barely functional and ran the game very slowly with graphics turned all the way down. It wasn't even Direct X 9 compliant, and I didn't know what I had been missing graphics-wise until I installed the 5500 mentioned above.

My 2 cents: If you can't afford to buy a new system, go with the 5500 mentioned above unless someone else has a better idea. And I'm sure someone does.

The VisionTek that CoReD mentioned looks like a great buy. At ~40 FPS, that's still pretty good for most gaming, though you might experience some lag in a first person shooter game. I think 2 GB Ram is probably more important for a strategy game like CIV4 / GALCIV2 to reduce lag. I have that plus a Radeon 9200 equivalent (an IGP) (definitely not a high end card).

The catch is that the system in this Dell system so pedestrian that you will need to sink extra cash (I guess about $400 on about 2GB ram, and probably a 3.0GHZ Prescott) and plan to hold onto to it for a few years instead of moving up to the dual-core system / socket 775 CPUs that have made the socket 478 extinct in the market. Else more than $50 is a waste if you'll just buy a LGA 775 system later (even the ram can't be recycled now).

If you're not planning on doing that here's some 256MB's:
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Description=pci+video&x=0&y=0

N.B. If Dell charged you more than $700 for that system, they pretty much ripped you off. I recommend building your own through NewEgg, having done that myself.

I've an old Athlon2400 w/1Gb RAM, and I upgraded some months ago to an already used GF6600GT. It was cheap (70 euro or so) at the time and should be even less now, and I've no prob at all with my games - GC2, but also Civ4 , and even Theater of War (but not full detail!).
I recommend this one !

A quick search on that model says that it comes with a video card (Riva TNT) that can't even run the game (at all). Couldn't find any details about what sort of slots it has either, but judging from what stats I could find, It'd be simpler and better to just go the new machine route.

Man that's rough trying to run the game on equipment like that. I'm running the latest $300 video card and the game isn't always smooth, but I think that's more my cheapo CPU than anything else. Most games just need a good video card, but I think GC2 needs a good CPU as well. Next build, I'm buying a good video card *and* a good CPU.

Unfortunately, GC2 can be pretty demanding as far as equipment goes. Dread Lords is more forgiving, but you need a good machine for Dark Avatar. There is hope for slower machines, but with limitations. You'll probably have to turn off some graphics options and play on smaller maps. If you want to play the game maxed-out, you definitely need some horsepower. I rebuilt my desktop machine a couple months ago with pretty good parts, but I did skimp on the CPU. The game bogs pretty bad when crunching turns later into a maxed-out Dark Avatar game. Though it's fine on Dread Lords. I could upgrade the CPU now, but I think I'll wait till my next build and try an Intel platform instead of AMD. I won't skimp on the CPU again.

I have a Dell Inspiron Laptop with the following specs:

Processor: Intel Pentium M 1.7GHz
Video: Ati Mobility X300, 128MB
Ram: 1GB DDR 2 (512MB + 512MB)

As you can see I have a low end gaming computer, and still I can play the game with NO-LAG at all, with the best video settings, and even anti-aliaising at 6x.

This game's video engine, and AI engine is pretty well done and optimized for low end computers like mine without sacrificing quality in the sake of performance.

Take a look at the various types of slots on your mainboard. Answers.com has a good pictorial.

http://content.answers.com/main/content/img/CDE/PCXSLOTS.GIF

I'm just going to assume that you have a PCI Express x16 slot for your video card.
You must also be mindful of how much power your new card uses as well. Dell skimps on Power supplies.

Also look for cards that use Stream Processors instead of PixelPipelines.

I know... it's a pain. But check this card out if you just want to see what I've picked out for you!

XFX PVT84JUSD4 GeForce 8600 GT 256MB 128-bit GDDR3 PCI Express x16 HDCP Ready SLI Supported Video Card

If you have a PCI slot as it appears you have, you have a better option than an NVIDIA Fx5500.
I upgraded from the NVIDIA Fx5500 to an Fx6200 OC from BFG.
It uses a 250watt minimum power supply and I have not had any problems with it.
It is DirectX 9.0c compliant.
It cost me about $75 US including shipping within the US.
You will get a very noticable improvement even over the Fx5500 - I sure did.
I have an HP desktop that is at least 2 years old, and this was the best upgrade that I could find.
The power supply on older HP desktops is proprietary, so it can't be upgraded with ease, so I was stuck.
I'm very impressed with the Fx6200 OC performamce - take a look at BFG's site and see.

Malcolm.