computer for medium gaming.

Your "ancient" CPU remains reasonably capable - it's a quad core, and you'll get relatively respectable efficiency in most video games. You don't need to improve it in the meanwhile.

besides the fact that children, your RAM is severely lacking in terms of ability - you want 8GB for gaming nowadays. if your motherboard supports 8GB of memory in complete, sell your current RAM and get 8GB of DDR2 memory. reckoning on your motherboard (you did not say which one you have) you're going to must either buy 2x4GB or 4x2GB.

The 2d component is that your pictures card also needs an improve - to at least Nvidia 750Ti or Radeon 260X. both of them would enable medium details with fps you mentioned, much more than that.

The comprehensive upgrade can also be executed inside the budget you mentioned, supplied you sell your historic graphics card and RAM first.