So I bought a bestbuy computer that has an AMD graphics card and the normal DVI plug from the motherboard. I bought 2 monitors and plugged one monitor in to the AMD GPU and the other to the Motherboard DVI yet only the AMD GPU monitor is working... I need help. I haven't downloaded any monitor drivers or anything..
It depends if the motherboard BIOS has the option to use both GPUs at the same time, check the motherboard BIOS. Alternately you will need to run both monitors off of the AMD GPU if not. There is no benefit from running one monitor on one GPU and one on another since running a monitor is very little work for a GPU to do. You may need a displayport to DVI adapter or whatever depending on what connectors the monitor has vs the ones on the GPU since you haven't given any details.