Do you have any network drives mapped? Also worth bringing up the task manager to see what processes are running; system may be having trouble shutting down a service. Look in the event log for any errors/warnings.
to close each program that is active one by one then- click turnoff- The machine will also complete any work you may have been doing and carrying out updates, and the Protection programs will be doing their thing too. The more you have had going the slower the shutdown. If you are a busy bee you could try 'Hibernate' instead. This save all work to disk and then on startup the machine returns to where you left it. Hibernate -hover mouse over 'Standby' then press 'Right Shift' click OK.