On windows 7 my volume icon is missing from the system tray

This can happen from time to time, but it is very rare and usually a restart will fix it.

The three solutions to try are (in order of convenience):

1. Restart the Windows Audio service.

   • open the Start menu
   • right-click on Computer and select Manage
   • navigate to "Services and Applications" → Services
   • right-click on Windows Audio and choose Restart

   

2. Restart Explorer.exe.

   • press Ctrl+Alt+Delete and select Task Manager
   • go to the Processes tab and find explorer.exe
   • right-click it and select "End Process". Make sure you do not have any file operations (copy/move etc.) going. Explorer should automatically restart.
   • If it doesn't, then in Task Manager, go to File → "New Task (Run...)", type in explorer, click OK and it should be back.

   

3. Restart the computer.

Go to control Panel, in that open Notification Area Icons

In that window in the bottom side click on the Turn System icons on or off please select on in the icon behaviour of volume, and click ok

....that's it