To find out which version of firmware you have, see this article.
Make sure that your AC adapter is plugged in. The Firmware Updater application will not run unless the computer is connected to AC power.
- Locate the appropriate update for your computer. Download it to your computer by clicking the update's title, then click the file size indicator in download details or at the bottom of the page. The download will place the disk image with an installer in your downloads folder or the location specified in Safari General Preferences. If you downloaded the disk image via Safari, Safari will notify you that an application is in the image. Click OK to continue.
- If "Open safe files after downloading" is checked in Safari preferences, the disk image file will mount by itself. If that preference is not enabled in Safari, double-click on the disk image to mount it.
- On the mounted disk image, you will find a file named MacBookAirFirmwareUpdate.pkg.
- Double-click MacBookAirFirmwareUpdate.pkg to start the firmware update process. (The installer puts the Firmware Updater in the /Application/Utilities folder, and opens it automatically.)
- Read the onscreen instructions and click Shut Down to proceed with the update. The firmware image will be loaded onto your computer. Your computer will shut down, but the update will not be installed until the next step.
- Turn on your computer but do NOT hold the power button down. Several seconds later, a gray screen with an Apple logo appears. There is a progress bar under the logo. As the progress bar moves, your firmware is being updated.
Important: Do not unplug, shutdown, or restart your computer while the update is taking place. Interrupting a firmware update can render your computer unusable.
Installation takes a few minutes.
- After your firmware has been updated, your computer will restart.
- After you log in, a dialog box stating the firmware update has been successful will appear. Click OK to dismiss this dialog.
If there is an installation issue
If the updater was not successful, your computer will automatically detect that there is a problem and restore the EFI ROM from your hard drive. When your computer restarts, you will see a progress bar while the ROM restores. After you computer restarts again, try installing again by opening the Firmware Updater application, which is located in the Utilities folder (/Application/Utilities). Then go to Step 4 above.
If you computer does not automatically recover, contact AppleCare for more information.
Important: An Intel-based Mac's hard disk must be formatted with the GUID partition scheme to apply a firmware update. Intel-based Macs are shipped this way from the factory. If you have reformatted your hard drive, you should check which scheme your hard disk is currently using before applying a firmware update. If you try to apply the update to a hard drive that utilizes any formatting scheme other than the GUID partition scheme the update will be unsuccessful.
Some USB devices may prevent firmware updates from installing correctly. If you are having trouble installing an update, try disconnecting non-essential devices and use only an Apple keyboard, mouse, and display.