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.

Once the process or application has been identified it is a matter of finding out why it is causing the delay. It could be outdated or incompatible with that version of Windows and to a lesser extent a faulty version or driver. A good way to start is to look for updates for that software and install those if they are available. It might be easier on the other hand to simply deactivate or uninstall the software if that is possible.