Upgrade your RAM. I have also 512 MB, it's pretty shitty. More RAM should give you shorter loading times, less lag and better gameplay, the graphics are less important I think.
ohh ok, What sould I be able to run my settings on with that outdated stuff? [i dont think u need any more info about my comp.] cause I ussaly put graphics way too high or low! help me and u get a 1+ ;]