How to Restart A Frozen Apple Computerby Elle Smith ; Updated September 28, 2017
Mac computers are stable and reliable computers, especially since the advent of OS X. At times, however, your computer may hang, seemingly suspended in time by the spinning beach ball of doom, which indicates that a program is not responding or is in an unrecoverable mode. If your computer is frozen and you can't shut down from the Apple menu, force-quitting or hard-restarting will generally take care of the issue.
Press "Command," "Option" and "Esc" simultaneously. The "Force Quit Applications" window opens. Highlight the open application in the list, then click the blue "Force Quit" button to close the application. Force-quitting an application may often be the only step you need to take to unfreeze your Mac.
Select the "Apple" menu and scroll to "Restart." If you're able to restart it through the Apple menu, this is the preferred mode.
Perform a hard restart by pressing down on the power button until the computer shuts off.
Wait a few minutes. Reboot your computer. Log in to your user account.
Try to save your work. You will lose your work if you shut your computer off using the power button.