Don't expect good gaming on a system like that, Core 2 Duo? Forget about it. Your going to need at least an i3 core CPU, preferably a quad. 8GB of RAM is standard these days, you HAVE to have that much if you expect decent results.
but then again, it all depends on what your trying to game on, if it's simple undemanding games like WoW or Minecraft and such, then requirements aren't as nearly as demanding, but Battlefield 3? Arma 2? Warfighter? Your going to need much more serious components.