If you want to add Mac Menu Extras functions (Clock, CPU, Displays, Spaces, and so on) in your menu line, or if you accidentally removed some items that you need, here's how you can easily set them in the menu line.
1. Open Finder.
2. In left panel, select Macintosh HD under Devices.
3. In the right panel, go into System, then the Library, CoreServices, and open the Menu Extras.
4. Then the list of files with .menu extension will show up. Double click on the desired Menu Extra function, and she will immediately be installed in the menu line. There are available to you the following Menu Extra items: AirPort, Battery, Bluetooth, Clock, CPU, Displays, Eject, Fax, HomeSync, iChat, Ink, IrDA, PCCard, PPP, PPPoE, RemoteDesktop, Script Menu, Spaces, Sync, TextInput, TimeMachine , Universal Access, User, Verizon, Volume, VPN, and WWAN.
If you want to remove any Menu Extras line item from the menu, simply hold press Command button, and then click on the icon which you want to remove from menu line.