Windows Shutdown usually takes only a matter of seconds before the computer shuts down. It can take longer if commands or applications are executed at shutdown. One of the better additions of the Windows Vista operating system is the advanced Event Viewer that can be used to analyze Windows shutdown performance problems easily. The very same possibility will be included in Microsoft’s next operating system Windows 7.
You can start the Event Viewer in Windows using the keyboard shortcut [Windows R], typing [eventvwr.msc] and hitting [enter]. Navigate in the Event Manager using the menu on the left side using the following path: Applications and Services Logs => Microsoft => Windows => Diagnostics-Performance => Operational. This will lead directly to the location that contains performance diagnostics not only for the Windows shutdown but also for standby and boot performance issues.
A good way to start is to sort the columns by Task Category. Click on the Task Category title and look for Shutdown Performance Monitoring entries. Each entry will contain information about the application or process that was causing problems during shutdown including the time it took to shutdown that process. A process that takes very long to shutdown is usually the problem for the shutdown problems.