When an item on the right side of the menu bar isn’t working right (Spotlight, the Airport icon, or something you added to the menu bar), you can often fix it without having to restart the computer.
Menu bar utilities are handled by a process called SystemUIServer. If you restart that process, everything on the right side of the menu bar reloads, which usually fixes any problems there.
To restart SystemUIServer:
1. Open Activity Monitor (It’s in the Utilities folder).
2. If you don’t see the Activity Monitor window, choose Window > Activity Monitor.
3. In the list, select SystemUIServer. If the list is long and SystemUIServer is hard to find, enter the name into the Filter box at the top of the Activity Monitor window.
4. With SystemUIServer selected, click the Quit Process button (or choose View > Quit Process), and then click the Quit button.
You’ll see SystemUIServer reappear in the list, because OS X restarts it automatically. The items at the right side of the menu bar should disappear, and then reload. In most cases, the problematic menu bar item should work correctly now.
If that doesn’t work, try logging out and then back in.
If that doesn’t work, try restarting.
The reason I don’t suggest logging out or restarting as a first course of action is that if you’re like me, you’ve constantly got multiple documents open in multiple applications and you don’t want to close it all down and set it all back up if it isn’t necessary.
Today I clicked on the Spotlight icon in the menu bar and it highlighted, but the Spotlight search menu wouldn’t appear. Restarting SystemUIServer fixed it, as usual.
Activity Monitor is a good place to quit or restart any process that doesn’t have its own Quit command.
And a final tip…you can rearrange most menu bar items by Command-dragging them. (Some menu bar items that appear at the left end may be put there by applications and can’t be rearranged.) You can also remove a menu bar item by Command-dragging it off the menu bar.