If your Apple Remote doesn’t work with Mac
The Apple Remote works only with Mac computers that have an infrared (IR) receiver. If your remote isn’t working, IR reception may be turned off on your Mac, or the remote may need a new battery.
Turn on IR reception
On your Mac, choose Apple menu > System Preferences, click Security & Privacy, then click General.
Click the lock icon to unlock it, then enter an administrator name and password.
In the window that appears, deselect “Disable remote control infrared receiver.”
Replace the Apple Remote battery
Apple Remote with seven buttons: Use a coin to remove the battery cover on the back of the Apple Remote. Remove the old battery and insert a new CR2032 battery, positive side up. Replace the cover and use a coin to tighten it.
Apple Remote with six buttons: Use a paper clip to press the battery compartment release button on the bottom of the Apple Remote. Slide out the battery tray, remove the old battery, insert a new CR2032 battery, positive side up, then slide the battery tray back into the Apple Remote until it clicks.