One of the things you'll want to look for is what type of ports are on your motherboard for video cards. I'll just list some common ones: AGP, PCI, PCIE
I am not looking to upgrade my current computer, which is a lousy e-machines! In fact, I think e-machines basically can't be upgraded. Not even worth it if they could. But I am looking to build my next computer so I am trying to find the best and at the same time affordable parts. So what should I look for?