As I suspected, it is an HP. Ok, HP piles on the background processes and many things they install can interfere with the game. From the Bluetooth drivers to Norton, you have your hands full.
A typical Vista system has about 35 to 38 processes running in the background. With the video card you have, you really need to make sure you disable the "Detailed Terrain" option in the games "Options->Graphic Detail->Advanced" panel.
That assumes you can get that far. Also note, if the game unexpectedly aborts, for whatever reason, it is quite possible for something to get corrupted (particulalry when Norton is installed) and would require a complete wipe of the game and re-install.
Getting rid of processes takes effort. You have to get the name of the process, then decide if you need it, then find the method to disable it, if you chose. Most of that starts with getting the name of the process, then heading to Google to find out all about it. HP is not going to help you with this.