live2fly

I have windows 7 64 bit. I have the free version for now just to try it before I buy the full version......and so far I am glad I have done so because even with the graphics set as low as I can get them it still laags really bad. Any idea as to why? Those of you have windows 7 64bit say it works great, so what is the problem with mine. Do I need to re-install, or could it be the free version has a problem or what? :confused: