Where's my sound volume icon ? 2 questions. is that legal ?

volume icon on lower right tool bar some time it's there and some time it's not.. i reboot and some time it appears and some time it doesn't. ques 2,, i get an e-mail at 7:30 this am and it says it was sent 15:15 today. 3:15 today hasn't even got here yet. do i need a new comp ??