I need some help with upgrading my video card in my PC.

I want to upgrade my video bad,here is my specs of my pc,I already upgrade my ram to the max of 2GB,so now it's time for a good card without upgraded my power supply,the total wattage 250?

A 8600GT/2600XT/3650 is probably the best you can do with 250 watts.

What CPU do you have?

Well 250W is going to be the main problem..
Every card I see that's of the newer generations require at least 450W and reccomend more,
and usually they require 2 4-pin molex connectors as well (those power cords inside the case going to everything)

We need more info tho,
Mainly does your board support AGP or PCIe