So basically, a year ago, I got a PC mainly for school. I really like it, but it is a work PC, so games like Rainbow Six Siege, Evolve, CS:GO and Skyrim need to be on low graphics. Even then they may start going at a slow FPS. So I've been wondering if I should get a new graphics card, as I don't have the sufficient funds to build a gaming PC. If I get a new graphics card, would I need a new processor/hard drive/CPU/motherboard? If I don't, could someone tell me what to buy at a reasonable price?