Plz help, video driver issue

Hello


i have a AMD Sempron 3400+ that has a onbord video card, i put a after market video card (fx 5700? i think it was) which failed, now i am back to the onbord card, which works. but is very choppy and dosent want to run my video games that it did once befor i added the aftermarket one, im trying to find out what kind of video card it is so i can up load the drivers. any info would be helpful thanks!