I don't think that the service pack cause problems it should repair...
Install Vista SP2 to resolve windows applications and drivers problems. Be sure you don't have a virus.
Vista Home on a Toshiba laptop Satellite A135. I've had this computer 18 months. About 3 months ago I switched to the Vonage phone system and needed to modify my DSL modem firewall settings. I then loaded Zone Alarm onto the laptop to be sure the new firewall settings were keeping the bad guys out. Zone Alarm required that I upgrade to SP1, which I did. Then the problem started. The Taskbar at the screen bottom frequently freezes. The clock stops running. When you move the cursor onto the Taskbar, it turns into a double headed arrow or an hourglass. When you click on a task on the Taskbar, a message box appears announcing that 'The application is not responding'. When you stop the application using the key in the message box, the whole screen is repainted and the problem is temporarily solved. I've tried to find out which task is not responding using the Task Manager, but I can not tell. I've thought of reloading Vista, but with all the updates, I'm not sure how that would work. I'm not even sure I could find the original disk. I could use some advice.