External graphics card for FSX

No external solutions are expensive and not worth the money!

Is there another solution besides putting a gpu in my pc

Do you mean you need dedicated GPU for your slim tower to play FSX?

Read this:
http://www.tomshardware.com/forum/328028-33-profile-gra...

Also list your specification.

Lenovo m58p. Extremely small. about the size of the new xbox slim.
Intel Pentium III xeon @ 3.00 GHz
upgraded RAM 4GB
sad 280 watt power supply
sad 140 GB hard drive(thinking of getting external one)
Win7 32 bit pro
Currently running integrated Q45/Q43 graphics.

With low graphics, high end add- on plane, and Fraps...I can get around 15-20 FPS with gamebooster running. I got as low as 2 fps once.

Sometimes my computer goes on steroids and runs at 50 fps with slightly blurry graphics.

My friend gave me his asus p6t motherboard.
I was gonna make a computer out of it but I calculated it would at least be $600 and I don't have that money laying around.

P IV, not P III xeon. This is the one right?

http://ark.intel.com/products/27094/64-bit-Intel-Xeon-P...

No point getting anything overly fast for GPU because of bottleneck. A 4670 will do. But then I have no idea whether it would fit or not.

Do you have the sff or usff? The usff doesn't even have a pcie slot but the sff can fit low profile cards.

That weak old CPU will never run FSX in a million years and since you cannot upgrade to a decent GPU anyway your only choice is to build a new rig from scratch to play FSX.