If you are a Mac user, you know the utility of the function keys. With a single button you can perform a global action, like changing the volume or brightness. Of particular use on a Mac is the F3 button, known as \u201cMission Control,\u201d which reveals all the open windows. But what happens when the F3 button unexpectedly stops working on a Mac? Read on to find out more about some common fixes for this problem, from resetting keyboard preferences to the \u201ckill all dock\u201d command.\n\n\n\nWhat To Do If Your F3 key Is Not Working?\n\n\n\nIf F3 does not take you to \u201cMission Control,\u201d there are several possible ways to fix the problem.\n\n\n\nRestart the computerUse \u201cSystem Preferences\u201d to change your keyboard settingsUse \u201cSystem Preferences\u201d to change your modifier keysReset the SMC for your computerReset the NVRAM for your computerUse a terminal program to run the command \u201cKillall dock\u201d\n\n\n\n1. Restart the computer\n\n\n\nAs anyone who has ever served as a tech assistant knows, the first and last solution to any problem is to restart the computer. Sometimes, when a system error has occurred or an update is pending, a simple restart will solve the problem. To restart your Mac, click the Apple icon on the top left and choose \u201cRestart.\u201d\n\n\n\n2. Use \u201cSystem Preferences\u201d to change your keyboard settings\n\n\n\nIf restarting doesn\u2019t work, you may need to change your keyboard settings. To do this, click on the Apple icon and choose \u201cSystem Preferences.\u201d From among the different options or icons available in System Preferences, choose \u201cKeyboard.\u201d\n\n\n\nIn the dialog window that appears, look for the sentence \u201cUse F1, F2, etc. keys as standard function keys\u2026.\u201d Next to it is a box that may be checked or unchecked. Try checking (or unchecking) this box and then exiting the window.\n\n\n\nIf \u201cUse F1, F2, etc. keys as standard function keys\u2026.\u201d is enabled (box is checked), you should be able to use the standard F3 function by pressing that key, or by pressing the \u201cfn\u201d button at the bottom of your keyboard along with F3.\n\n\n\n3. Use \u201cSystem Preferences\u201d to change your modifier keys\n\n\n\nThere is another way to use \u201cSystem Preferences\u201d to fix your F3 key. Click the Apple icon, choose \u201cSystem Preferences,\u201d find the option\/icon for \u201cKeyboard,\u201d and in the resulting dialog window look for a button labeled \u201cModifier Keys.\u201d\n\n\n\nPressing this button should open a new dialog window that lists the assigned function of some of the keyboard keys. Check to see if your \u201cfn\u201d key is currently assigned to another function by clicking on the dropdown list. From the list, choose \u201cfn function\u201d or click on the button labeled \u201cRestore defaults.\u201d\n\n\n\n4. Reset the SMC for your computer\n\n\n\nIf these typical fixes using System Preferences and Keyboard Settings don\u2019t work, there are several other options you can try.\n\n\n\nThe SMC, or \u201csystem management controller,\u201d handles all kinds of system functions from thermal controls and battery charging to sleep\/wake and keyboard controls. To reset your computer\u2019s SMC, the process differs slightly depending on what type of Mac you use. Some Macs have a different type of internal chip that handles secure operations (those that involve touch sensors\u2014like keyboards\u2014or passwords).\n\n\n\nFor a Mac that has a new M1 chip there is no SMC, so a simple restart should work. For computers with a T2 chip, like Macbook Pro or Macbook Air, press and hold the right Shift key, the left Option key, and the left Control key for at least seven seconds, then also press the power button and hold for at least seven seconds to restart the computer. For an older computer with a T1 chip, press and hold the Shift, Option, and Control keys on the left side, then press the power button and hold all of these keys down for ten seconds as the computer starts up. Resetting the SMC may restore your F3 key.\n\n\n\n5. Reset the NVRAM on your computer\n\n\n\nNVRAM is a section of your computer\u2019s memory that stores a few important pieces of information about how the computer works, including details about things like the startup disk and screen resolution. Resetting it may help restore your keyboard function. To reset NVRAM, shut down your computer and when restarting, hold down the Command, Option, P, and R keys. Continue to hold these keys for at least twenty seconds. On an older MAC that chimes at startup, you should hear a second chime before you release the keys and allow it to boot normally. This fix may solve your F3 problem.\n\n\n\n6. Use a terminal program to run the command \u201ckillall dock\u201d\n\n\n\nIf your F3 key still isn\u2019t working, you can try opening a terminal program and entering the command, \u201cdillall dock.\u201d This command restarts the computer\u2019s \u201cdock\u201d of applications at the bottom of the screen, restoring them to the default configurations. Those docked applications typically include the \u201cMission Control\u201d app tied to the F3 key, so restarting the dock may restore its function.\n\n\n\nWhat is a function key?\n\n\n\nLike PCs, most Macintosh computers have a row of keys labeled F1 to F12 across the top of the keyboard. Unlike most PCs, a Mac\u2019s F1 to F12 keys are linked to a particular action, like increasing or decreasing volume or brightness. Some Mac laptops now have a small touch strip in this area instead. To reveal the standard function keys, you can still press the \u201cfn\u201d button at the bottom of the Mac keyboard.\n\n\n\nWhat is the F3 key on a Mac?\n\n\n\nTypically, the F3 key on a Mac performs a kind of \u201cZoom out\u201d from whatever application you are currently using, revealing all the apps that are currently in use. This function, called \u201cMission Control\u201d because it returns you to the center of all your current operations, may also appear as a rocket icon on the dock of apps at the bottom of your screen.