1. Update your video drivers
here, the model number for your laptop will be located on the underside, on the silver Toshiba sticker. The ATI/Nvidia site may or may not have newer drivers, but for a model as old as yours, I'm assuming the Toshiba driver section will have the latest.
2. Defrag your hard-drive and run a disk check to see if there are any bad sectors.
I'd recommend using TuneUp Utilities 2009, you can google for it, the 30 day trial works perfectly fine and has all of the features.
3. Check the Video settings for your game, you will most likely have to manually edit a settings file located within the game directory.
4. If the above fails, re-install the game.
5. If that fails, reformat and reinstall Windows, if you're really willing to.
Chances are your Video settings are set too high for your Laptop to handle.
You could also have a corrupted game file, in which case you'll have to reinstall, but follow the first two steps anyways, it's better for the computer and it's a good practice to get into.