|The best advice I can give you to get better gaming performance is to purchase a new machine... Seriously.|
I do not know the AMD CPU's well but by the base clock speed, it is not going to be much of a CPU for gaming. Then there is the integrated graphics which is not for gaming either. Add to that the fact that you cannot change either of these things (no room for distinct graphics card and would not have the proper cooling capability anyway).
To do any significant gaming you should look for a mid tower case, a modern dual or quad CPU significantly faster than what you have, a distinct gaming level graphics card, and components chosen specifically for gaming. If you are not able to choose the components and build it yourself then look for a local computer shop (get recommendations) that can build one for you and your budget. If you need to cut corners initially, make sure that the components that you will not as easily or cheaply replace are near top tier (motherboard, CPU, and power supply) since it is simple to add more memory and replace the graphics card, etc as future upgrades,
You have to be a little bit crazy to keep you from going insane.