That system is not build with gaming in mind. I may even have a weak onboard video card instead of the dedicated cards gaming systems would have. A 2 year old mid level desktop card gets about 7-7.5 and even that will not max out modern games. The Windows experience index is not a great indicator anyway.
2 gigabytes of memory is also low for a gaming system.
Replacement with a newer system is about the only thing that would be faster because it is not likely to be upgradable.