Will a Nvidia 6200 work for Fallout 3?
It has:
NVIDIA? GeForce? 6200 GPU
512MB DDR2 Memory
64bit data bus
TV-Out,VGA and DVI-I
AGP8X interface
DirectX 9.0
OpenGL 2.0
Vertex Shader 3
Pixel Shader 3

My grandparents had an Integrated 6200 and it worked fine.

I doubt it, the minimum supported card is the 6800. Even if you did manage it, you'd have to lower all the settings completely to the point that it would look like crap and it would still lag. If it worked fine with your grandparents, then I doubt they had a 6200. The game would have played like a slide show.

Yeah. They had an integrated 6200 and the graphic options were all at minimum. This is an actual add-on card so maybe it will be a little faster because it doesn't have to deal with all the traffic between the CPU and the busses <-- I know this is true because I'm in an actual computer class and you learn a lot there! When I played on that Integrated 6200 I literally could not see 10 ft in front of my character, so maybe this card will.

The onboard versions of the 6200 were the 6100, 6150, 7050, and 7150, and all of them, plus the 7100 and 7200 discrete cards, shared the shader defects of the 6200, which can do such neat things as render a cloudy sky as a checkerboard. The 6200 started life as a closely related design to the 6600, but was too expensive to produce to sell at the price point it needed to fit into, so the 6200A had the memory system greatly crippled (64 bit instead of 128 bit) in order to cheapen it, and it was the "A" that gave birth to the various awful IGPs in the nVIDIA chipsets.

None of those 6100 to 7200 parts are worth spit, not as IGPs, and certainly not as gaming graphics cards.

http://www.gpureview.com/show_cards.php?card1=198&card2=354

The 6200A is one-tenth as good as the 6800.

G.

My motherboard only has an AGP slot pus I don't have enough to buy a 500 watt power supply to go alomg with a DX 10 AGP card saw.

The minimum Geforce was a Dx9 card, not Dx10, and you cannot buy one new any more, It was new six years ago. The first Geforce Dx10 cards were the 8n00 generation, but you can't modify one of those to fit into an AGP slot, and it would be very difficult to find a new one now, were that an actual option.

Only ATI ever made any Dx10 cards for AGP. nVIDIA stopped AGP with the 7n00 generation, and Dx9, while AMD went on covering that type through their HD 4n00s. They cost half again more than PCIe cards, though. You can still buy the PCIe version of an HD 4650 for about $50, maybe $60, but the AGP version, when you can locate one, will be $70-$75.

I believe that the last 256 bit card for AGP, the HD 3850, was Dx10, but yes, it would want more juice than any brand name PC's original equipment power supply, while the HD 4650 would work with a 250 watt unit that had not worn out completely (power supplies wear out on PCs when only the cooling fans and displays are dying).

Radeon 4650 in AGP:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102851&cm_re=radeon_4650_agp-_-14-102-851-_-Product