Ah... Vista. You gotta love this OS.
Almost certainly the graphics drivers for Vista are the problem. You are not alone, Toshiba is not alone, NVidia is not alone. After all this time, drivers support for Vista is apparently still a major headache for Vista users under a large number of different systems.
The answer to your problems is... you guessed it... Windows XP. Toshiba is poised to have XP drivers for your system. And I can almost bet NVidia own default XP drivers can run on your laptop without any problems, which would free you from Toshiba custom made drivers.
