How to resolve vertual memory issue on lenovo laptop?

How can I resolve vertual memory issue on my laptop I have lenovo g5070 model with 1tb hdd and I created 4 partions over it,2 gb ati radon graphic card, with 4 gb ddr3 ram and the processor is core i3 1.3ghz, whn I play the heavy graphics game just like mostwanted 2 racing game its show error while playing the game "your vertual memory is too low" and windows will close the programme and currently my system vertual memory is set by default 512 mb… So how can I enjoy my game without interruption… Suggest me what I have to do to resolve this issue… Thank you in advance