AppleCare+ for Mac Every Mac comes with a one-year limited warranty and up to 90 days of complimentary technical support.AppleCare+ for Mac extends your coverage to three years from your AppleCare+ purchase date and adds up to two incidents of accidental damage protection every 12 months, each subject to a service fee of $99 for screen damage or external enclosure damage, or $299. Your MacBook Air comes with 90 days of complimentary technical support and a one-year limited warranty. Purchase AppleCare+ for Mac to extend your coverage to three years from your AppleCare+ purchase date and add up to two incidents of accidental damage coverage, each subject to a service fee of $99 for screen damage or external enclosure damage, or $299 for other repairable damage, plus. Download Mac Lion Installer from App Store. Latest versions of Mac are only available through App.

USB port types and names

USB (Universal Serial Bus) is an industry standard for connecting computers and other devices. It's available with many types of ports, and each type has a unique shape. On Mac computers, USB is available with these ports, depending on your Mac model:

USB-A

Type USB-A ports are commonly called USB, USB 2, or USB 3 ports, depending on the USB specification they support. They aren't reversible, so a USB-A connector plugs into the port only when oriented correctly.

USB-C

Type USB-C ports are available as either standard USB-C ports or Thunderbolt 3 ports that also support USB-C connections. They both look the same, and the connector plugs into the port in either orientation.

Learn more about identifying the ports on your Mac, as well as the adapters and cables you can use to connect older devices to type USB-C ports.

USB specifications

USB specifications are important primarily when you want the most speed and power for your USB device, or your device needs more power or is using too much power. Every USB port supports a particular USB specification, which determines the port's maximum>USB specifications on MacData transferPowerUSB 3.1 Gen 2
Also known as USB 3.2 Gen 2
Up to 10 GbpsUp to 15W at 5VUSB 3.1 Gen 1
Also known as USB 3.2 Gen 1 or USB 3
Up to 5 GbpsUp to 900 mA at 5VUSB 2.0
Up to 480 MbpsUp to 500 mA at 5VUSB 1.1
Up to 12 MbpsUp to 500 mA at 5V

To learn which specification is supported by a type USB-A or type USB-C port on your Mac model:

Choose Apple menu  > About This Mac, click Support, then click Specifications.
Check the System Information app for more details, including about USB devices connected to USB ports on your Mac. Select USB in the sidebar, then select a USB bus on the right.

Usb For Mac Air

Get the best performance from your USB devices

USB specifications all work with each other, but speed and power are limited by the cable or device that uses the earliest specification. For example, if you connect a USB 3 device to USB 2 port, your device is limited to USB 2 speeds, and it can't draw more power from the port than can be delivered over USB 2. In other words, to get the best performance, make sure that the USB port on your Mac and the USB cable to your device meet or exceed the USB specification of the device itself.

If your Mac doesn't recognize a USB device after you plug it into your Mac:

Check all connections: Unplug the device from your Mac, then plug it back in, and make sure that all cables and adapters are securely connected at both ends. Test with another cable or adapter, if available.
Plug the device directly into your Mac instead of a USB hub or other device, and if necessary test with a different USB port on your Mac or device.
Some devices need their own software, such as drivers or firmware. Others work without additional software. Check with the maker of your device, and install all available Apple software updates as well.
If your device came with an AC power adapter, use it. Some devices can be powered by the USB port on your Mac. Others need more power than your Mac can provide.
Restart your Mac.

Learn more

USB 3 devices can create wireless interference that affects Wi-Fi and Bluetooth devices. Learn how to resolve Wi-Fi and Bluetooth issues caused by wireless interference.
Mac notebook computers with USB-C or Thunderbolt 3 can charge over that port using a compatible USB-C power adapter and cable.

These advanced steps are primarily for system administrators and others who are familiar with the command line. You don't need a bootable installer to upgrade macOS or reinstall macOS, but it can be useful when you want to install on multiple computers without downloading the installer each time.

Download macOS

Find the appropriate download link in the upgrade instructions for each macOS version:

macOS Catalina, macOS Mojave, ormacOS High Sierra
Installers for each of these macOS versions download directly to your Applications folder as an app named Install macOS Catalina, Install macOS Mojave, or Install macOS High Sierra. If the installer opens after downloading, quit it without continuing installation. Important: To get the correct installer, download from a Mac that is using macOS Sierra 10.12.5 or later, or El Capitan 10.11.6. Enterprise administrators, please download from Apple, not a locally hosted software-update server.

OS X El Capitan
El Capitan downloads as a disk image. On a Mac that is compatible with El Capitan, open the disk image and run the installer within, named InstallMacOSX.pkg. It installs an app named Install OS X El Capitan into your Applications folder. You will create the bootable installer from this app, not from the disk image or .pkg installer.

Use the 'createinstallmedia' command in Terminal

Usb Adapter For Mac Air 2019

Connect the USB flash drive or other volume that you're using for the bootable installer. Make sure that it has at least 12GB of available storage and is formatted as Mac OS Extended.
Open Terminal, which is in the Utilities folder of your Applications folder.
Type or paste one of the following commands in Terminal. These assume that the installer is still in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you're using. If it has a different name, replace MyVolume in these commands with the name of your volume.
Catalina:*
Mojave:*

High Sierra:*
El Capitan:
Press Return after typing the command.
When prompted, type your administrator password and press Return again. Terminal doesn't show any characters as you type your password.
When prompted, type Y to confirm that you want to erase the volume, then press Return. Terminal shows the progress as the bootable installer is created.
When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as Install macOS Catalina. You can now quit Terminal and eject the volume.

* If your Mac is using macOS Sierra or earlier, include the --applicationpath argument, similar to the way this argument is used in the command for El Capitan.

Use the bootable installer

After creating the bootable installer, follow these steps to use it:

Plug the bootable installer into a compatible Mac.
Use Startup Manager or Startup Disk preferences to select the bootable installer as the startup disk, then start up from it. Your Mac will start up to macOS Recovery.
Learn about selecting a startup disk, including what to do if your Mac doesn't start up from it.
Choose your language, if prompted.
A bootable installer doesn't download macOS from the Internet, but it does require the Internet to get information specific to your Mac model, such as firmware updates. If you need to connect to a Wi-Fi network, use the Wi-Fi menu in the menu bar.
Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructi