Install Osx From Flash Drive
Click and drag the IMac OS X Install ESD from the left pane and drop it in the Source field; Then Click and Drag the USB drive from the left pane and drop it in the Destination field; Make sure you have chosen the right USB drive, you don’t want to format the wrong drive and then click on Restore button. The steps below will guide you through how to Install OS X Snow Leopard from a USB Flash Drive. Alternatively, you can also read these instructions on how to install OS X Lion from a USB Flash Drive. Apple officially released Snow Leopard a couple years ago and consumers can still find the latest version of OS X. The process of installing OS X or macOS on a Mac hasn't changed a great deal since OS X Lion altered the delivery of the OS from optical disks to electronic downloads, using the Mac App Store. The big advantage of downloading the Mac OS is, of course, immediate gratification (and not having to pay shipping charges).
Editor’s note: We've updated this guide for the release version of El Capitan (OS X 10.11), which was released on September 30, 2015.
When OS X shipped on a DVD a good number of years ago, you always had the convenience of a bootable installer—an OS X installer that could be used to boot your Mac if its own drive was having problems. But to install or reinstall a recent version of OS X, you must either download a non-bootable installer from the Mac App Store or (via OS X’s invisible, bootable recovery partition) download 6GB of installer data from Apple’s servers during the installation process. In other words, you no longer have the same safety net or convenience.
Because of this, I recommend creating your own bootable El Capitan (OS X 10.11) installer drive on an external hard drive or USB thumb drive. If you need to install El Capitan on multiple Macs, using a bootable installer drive is faster and more convenient than downloading or copying the entire installer to each computer. If you want to erase the drive on a Mac before installing El Capitan, or start over at any time, you can use a dedicated installer drive to boot that Mac, erase its drive, and then install the OS (and subsequently restore whatever data you need from your backups). And if your Mac is experiencing problems, a bootable installer drive makes a handy emergency disk.
(OS X Recovery lets you repair your drive and reinstall OS X, but to perform the latter task, you must wait—each time you use it—for the entire 6GB of installer data to download. At best, that’s a hassle; at worst, it’s hours of waiting before you can get started.)
As with previous versions of OS X, it’s not difficult to create a bootable installer drive, but it’s not obvious, either. I show you how, below.
Macworld also has bootable-install-drive instructions for Yosemite (OS X 10.10), Mavericks (OS X 10.9), Mountain Lion (OS X 10.8), and Lion (OS X 10.7).
Keep the installer safe
Like all recent versions of OS X, El Capitan is distributed through the Mac App Store: You download an installer app (called Install OS X El Capitan.app) to your Applications folder. In this respect, the OS X installer is just like any other app you buy from the Mac App Store. However, unlike any other app, if you run the OS X installer from that default location, the app deletes itself after it's done installing OS X.
If you plan to use the OS X installer on other Macs, or—in this case—to create a bootable installer drive, be sure to copy the installer to another drive, or at least move it out of the Applications folder, before you use it to install the OS on your Mac. If you don't, you'll have to redownload the installer from the Mac App Store before you can use the instructions below.
What you need
To create a bootable El Capitan installer drive, you need the El Capitan installer from the Mac App Store and a Mac-formatted drive that’s big enough to hold the installer and all its data. This can be a hard drive, a solid-state drive (SSD), a thumb drive, or a USB stick—an 8GB thumb drive is perfect. Your drive must be formatted as a Mac OS Extended (Journaled) volume with a GUID Partition Table. (Follow this tutorial to properly format the drive if you're using OS X Yosemite or older. If you're using OS X El Capitan, use these instructions.)
Your OS X user account must also have administrator privileges.
Apple’s gift: createinstallmedia
In my articles on creating a bootable installer drive for older versions of OS X, I provided three, or even four, different ways to perform the procedure, depending on which version of OS X you were running, your comfort level with Terminal, and other factors. That approach made sense in the past, but a number of the reasons for it no longer apply, so this year I’m limiting the instructions to a single method: using OS X's own createinstallmedia tool.
Starting with Mavericks, the OS X installer hosts a hidden Unix program called createinstallmedia specifically for creating a bootable installer drive. Using it requires the use of Terminal, but createinstallmedia works well, it's official, and performing the procedure requires little more than copying and pasting.
The only real drawback to createinstallmedia is that it doesn't work under OS X 10.6 Snow Leopard—it requires OS X 10.7 Lion or later. Though it's true that some Macs still running Snow Leopard can upgrade to El Capitan, I think it’s safe to assume that most people installing OS X 10.11 will have access to a Mac running 10.7 or later.
(If you absolutely refuse to go near Terminal, an El Capitan-compatible version of DiskMaker X is now available, although I haven't yet had the chance to test it.)
Making the installer drive
- Connect to your Mac a properly formatted 8GB (or larger) drive, and rename the drive
Untitled. (The Terminal commands I provide here assume that the drive is named Untitled. If the drive isn’t named Untitled, the procedure won’t work.) - Make sure the El Capitan installer (or at least a copy of it), called Install OS X El Capitan.app, is in its default location in your main Applications folder (/Applications).
- Select the text of the following Terminal command and copy it. Note that the window that displays the command scrolls to the right.
- Launch Terminal (in /Applications/Utilities).
- Warning: This step will erase the destination drive or partition, so make sure that it doesn’t contain any valuable data. Paste the copied command into Terminal and press Return.
- Type your admin-level account password when prompted, and then press Return.
- You may see the message “To continue we need to erase the disk at /Volumes/Untitled. If you wish to continue type (Y) then press return:” If so, type the letter Y and then press Return. If you don't see this message, you're already set.
The Terminal window displays createinstallmedia’s progress as a textual representation of a progress bar: Erasing Disk: 0%... 10 percent...20 percent... and so on. You also see a list of the program’s tasks as they occur: Copying installer files to disk...Copy complete.Making disk bootable...Copying boot files...Copy complete. The procedure can take as little as a couple minutes, or as long as 20 to 30 minutes, depending on how fast your Mac can copy data to the destination drive. Once you see Copy Complete. Done., as shown in the screenshot above, the process has finished.
Install Osx From Usb Drive Windows
Createinstallmedia will have renamed your drive from Untitled to Install OS X El Capitan. You can rename the drive (in the Finder) if you like—renaming it won’t prevent it from working properly.
Booting from the installer drive
You can boot any El Capitan-compatible Mac from your new installer drive. First, connect the drive to your Mac. Then, restart your Mac (or, if it's currently shut down, start it up) while holding down the Option key. When OS X’s Startup Manager appears, select the installer drive and then click the arrow below it to proceed with startup. (Alternatively, if your Mac is already booted into OS X, you may be able to choose the installer drive in the Startup Disk pane of System Preferences, and then click restart. However, sometimes OS X installer drives don't appear in the Startup Disk window.)
Once booted from your installer drive, you can perform any of the tasks available from the OS X installer’s special recovery and restore features. In fact, you'll see the same OS X Utilities screen you get when you boot into OS X Recovery—but unlike with recovery mode, your bootable installer includes the entire installer.
By default, your Mac starts up from its built-in hard disk, but a startup disk can be any storage device that contains an operating system compatible with your Mac. For example, if you install macOS on an internal or external drive, your Mac can recognize that drive as a startup disk. You can then follow the steps in this article to start up from it.
Use Startup Disk preferences
When you use Startup Disk preferences to select a startup disk, your Mac starts up from that disk until you choose a different one.
- Choose Apple () menu > System Preferences, then click Startup Disk.
- Click and enter your administrator password.
- Select your startup disk, then restart your Mac.
If you see a message that your security settings do not allow this Mac to use an external startup disk, check the External Boot setting in Startup Security Utility.
Use Startup Manager
When you use Startup Manager to select a startup disk, your Mac starts up from that disk once, then returns to using the disk selected in Startup Disk preferences.
- Press and hold the Option key immediately after turning on or restarting your Mac.
- Release the Option key when you see the Startup Manager window.
If your Mac is protected by a firmware password, you can release the key when you're asked to enter the password. - Select your startup disk, then click the arrow under its icon, or press Return.
If you press and hold the Control key during this step, your selection is saved in Startup Disk preferences, so it persists until you change it.
If your Mac is using OS X Lion 10.7.3 or later, you can also use this method to start up from your Time Machine backup disk. Startup Manager identifies your Time Machine backup as ”EFI Boot.”
If you can't select your startup disk or start up from it
Check for these possibilities if you can't see your disk in Startup Disk preferences or Startup Manager, or your Mac won't start up from it.
Check for a valid operating system on the startup disk
Make sure that your startup disk is using a version of macOS that's compatible with your Mac. You might need to reinstall macOS on that disk.
Check startup security settings
If you're using a Mac that has the Apple T2 Security Chip, check the settings in Startup Security Utility. These settings determine whether your Mac can start up from another disk.
Check for Option ROM firmware
Install Osx From Thumb Drive
If you're in Startup Manager and can't see your startup disk, press Option-Shift-Command-Period. If that works, do this each time you want to start up from the device or from a startup disk connected to it.
To enhance system security, Mac computers with up-to-date software don’t show devices that have Option ROM firmware until you press these keys in Startup Manager to load the firmware. On Mac models from early 2015 or earlier, you can disable this security feature to load Option ROM firmware automatically. This removes an important protection against potential unauthorized access to your Mac by other people with physical access to it.
- Open the Terminal app, which is in the Utilities folder of your Applications folder.
- Type
sudo nvram enable-legacy-orom-behavior=1, then press Return.
To undo this command, entersudo nvram -d enable-legacy-orom-behavior.
If you're using a firmware password on your Mac, the ability to load Option ROM firmware automatically or manually is disabled as an additional security protection. If you want to remove this additional protection but keep your firmware password:
- Open the Terminal app, which is in the Utilities folder of your Applications folder.
- Type this command, then press Return:
sudo firmwarepasswd -setmode command -allow-oroms
To undo this command, entersudo firmwarepasswd -setmode command. - Type the administrator password for your user account, then press Return.
- Type your firmware password, then press Return.
- Restart your Mac.