Hi
your pc configuration is much lower. i have faster computer and better graphics than yours but also i couldn't run GTA smoothly. So, you need at least 2gb of ram, core 2 duo processor(for best result) and above all better graphics because the series of yours is way older compared to the tech spec game use. So better upgrade your ram and buy latest graphic card( nVIDIA 9800 or above) with at least 512 of ram.
this might help you!