It recommends that dual-core CPUs like yours should be overclocked, so if you don't want to go down that path, then a simple upgrade to a quad-core will suffice. Integrated graphics (which I assume you're using) usually can't run anything 3D past 2005ish with a clean framerate, so that should definitely be on the upgrade list. Anything above $80 in GPUs can handle most games with at least 40-50 FPS, at least on medium settings, given a more recent game. Everything else looks fine. You could also upgrade to the more standard 8GB RAM, but 4GB should be fine.