I can't understand why, my specs:

Windows Vista Home Premium
Intel(R) Pentium(R) D CPU 2.80GHZ
1.00GB RAM
NVIDIA GEForce 7500 LE

Yet I am forced to play it on the lowest resolution and on low detail to actually get a really smooth picture, unlike most who can play it on 1024x768. Any advice. I've heard people saying the 7500 LE isn't a gaming card. Could that be the problem?