Why does Windows Vista take time to shutdown?

It may so happen sometimes that the Windows Vista may take time to shutdown sometimes, and this can be due to different reasons (such as Windows installing updates, crashed applications, or driver problems). If this happens more frequently, it indicates that this problem shouldn't be happening and is worth troubleshooting.

Start by loading the event viewer "eventvwr.msc" from the run box (press WINDOWS KEY + R to start this).