Installing Mac OS X

With your Mac powered off, insert your USB installer drive into your Mac and power on your Mac while holding down the Option key. If you are using a PC keyboard, the Option key is usually the ALT key on the left side of the keyboard. Keep holding the Option key until you are presented with the boot options screen, showing icons for each bootable drive.

Once at the boot options screen, select the USB icon representing the USB installer drive and press the Enter key to proceed.

If prompted, select your desired language.

Next, the installer environment and utilities will load.

If you have a new hard disk or a hard disk that hasn’t been formatted for Mac, you will need to format it before installing OS X. To do this:

1. Open Disk Utility.
2. Select your hard drive from the left sidebar. It should be the topmost item within the left sidebar. If you don’t see it, go to View > Show All Devices.
3. Click the Erase button at the top of the window.
4. Choose a new name for your Mac’s hard drive.
5. Change the format to Mac OS Extended (Journaled).
6. Under scheme, select “GUID Partition Map “if it is not already selected by default.
7. Click Erase.
8. When the process is complete, press command+Q to close Disk Utility.

Now Select Utilities, then Install OS X, then select Continue. Note: Some Mac installations will take several seconds for the install prompts screens to appear. Once the first install prompt screen appears, proceed following the on-screen instructions to upgrade/restore OS X on your Mac as you normally would.

In about 45-60 minutes (with several reboots) OS X should install on your Mac.

Troubleshooting

“This Disk is Locked”

If you are trying to install Mac OS X to your hard drive and you can’t select it, but you see the message, “This disk is locked” under the “Mac OS X Install ESD” drive. This is normal. The “Mac OS X Install ESD” drive is the USB drive that you purchased from us and should be locked. If you can’t select your hard drive for installation, it means that you’ll need to format it for Mac before installation can continue. Please see the section above for formatting instructions.

Using Google with a search phrase like ‘format hard drive for mac os lion/mountain lion/sierra” etc. will located many web pages on the topic as well.

System Clock Issue

If you see the message ““An error occurred while preparing the installation. Try running again.” it most likely means that the system clock on your Mac needs to be set to a new date. Here is how to fix that:

1. Turn your Mac off 
2. Insert USB installer drive into your Mac
3. Power up and hold the Option key down as soon as you hear the startup chime.
4. Once your at the installer screen, click "Utilities" from the menu at the top of the screen, and then click "Terminal".

In the terminal window, type in the following line:

date 1215134522

And press ENTER. That will set the date to December 15,2022 and should allow the install to successfully continue. After installation is complete, you can set the current date using OSX from the desktop.

After entering the date command from above, shut down your Mac and restart the installation.

Resetting NVRAM/PRAM

Your Intel based Mac contains a small amount of Non-Volatile RAM used by your Mac to control the configuration of various systems and devices. Resetting this RAM can sometimes fix install issues.

To reset NVRAM/PRAM, do this:

Shut down your Mac.

Turn your Mac back on.

Immediately press and hold the following keys: Command+Option+P+R. That’s four keys: the command key, the option key, the letter P, and the letter R. You must press and hold these four keys before you see the gray screen during the startup process.

Continue to hold down the four keys for at least 20 seconds

Finally, when you hear the second startup chime, you can release the keys.

Power down your Mac and the attempt to install OS X again.