I assume that you have tried to run the program using "Run as Administrator", if not right click the program in question and click "Run as Administrator" first to see if the program will run under normal conditions.
If you want to disable Norton, disconnect from the internet first, then right click on the Norton icon in the system tray and disable auto protect. Before you do this be aware that auto protect might not re-enable. Just make sure that you have the update that Symantec put out that makes Norton Vista compliant. J.B.