Finder is the OS X process that manages the desktop and file system browser, and is the app you need to keep running in order to use the Mac desktop as intended. Restarting Finder sometimes is the only way to troubleshoot strange Mac desktop behaviours. Instead of logout-and-login or a full system reboot, OS X has built-in shortcuts to relaunch Finder in a less obtrusive manner.
Option + Right Click
Hold down on ⌥ Option key and right click on Finder’s icon on the dock. Click to select the “Relaunch” option on the pop-up menu. If you’re using trackpad, use two-fingers tap for the mouse right click.
Force Quit Window
Open the “Force Quit Applications” window by pressing Command ⌘ + Option⌥ + Esc keys. Select “Finder” from the menu and click on the “Relaunch” button.
Finder can be restarted from the Terminal command line by entering the following: