what would you do if your shutdown icon is missing ?????????????

If the left button is missing so you can't assign it to shut down your computer, you may need to make a change to your group policy:-

1:- Start
2:- Run
3:- regedit
4:- go to HKEY_CURRENT_USER \ SOFTWARE \ MICROSOFT \ WINDOW \ CURRENT VERSION \ POLICIES \ EXPLORER
5:- On the right hand panel, delete the key NoClose
6:- Log off and back on again