Hi! I've finally decided to upgrade my old Optiplex 980 to try to make it a gaming computer, and was wondering how I can actually do this. The computer runs an Intel Core I7 processor, 32 bit OS (planning on upgrading to 64 bit Windows 8.1), 4 GB ram, and runs at about 2.93 GHz at the moment. What can I upgrade on this computer to make it usable for gaming? I'm looking to spend around 200$, but preferably less so I can upgrade my keyboard, mouse etc. Thanks so much in advance!