If you need, use TransMac to delete kexts which are causing problems (System/Library/Extensions) and delete kernelcache (System/Library/Caches//Startup) For other BIOS use legacy boot to install, you can fix UEFI boot later If you want to use Chameleon press 1 at boot If the problem persists, disable your anti-virus software, it may be blocking raw write to the drive. When Windows asks if you want to format it, cancel and run Image Writer again. If you have error during copy, eject and re-connect the pen drive. I hope this step-by-step with image explanation is very clear for you when creating a USB boot disk for your Mac.Access chat to get download link (channel topic). You can also select it in the Startup Disk preference for the next boot. To use it, reboot your Mac and press Option key while booting. After a couple of minutes, the OS X USB boot disk is ready. At this step, it may take a long time (15 minutes or more) while copying the files. Click ‘Erase then create the disk’ buttonĦ. You will be warned that the whole content of data in the USB thumb drive will be erased. Confirm with the USB thumb disk selection in the next step.ĥ. As I use an 8 GB of SanDisk, I select the ‘An 8 GB USB thumb drive’ button. Select the kind of disk you will use for the boot disk. Make sure that the path is correct and then click ‘Create a boot disk’ button.Ĥ. After you click one of the version of OS X above, the application is smart enough to search and detect the available image in the HDD or SSD. This application is able to create a boot disk of Lion (10.7) and Mountain Lion (10.8)ģ. Unzip and run the application, and then select which OS X version you want to make a boot disk of. Format the USB flash disk with Mac OS Extended (Journaled) file system type using Disk UtilityĢ. Here are the step-by-step on how to easily create OS X Mountain Lion USB Boot Disk / Installerġ. For example, I use an 8 GB of SanDisk Cruzer Blade. Since the size of the OS X image is more than 4 GB, you need an 8 GB USB flash drive. You can create a USB stick installer for OS X Mountain Lion.

If you wish to install / upgrade other Mac computers, you don’t need to re-download from the App Store. Skip the step by pressing Quit button.Ĭopy the ‘ Install OS X Mountain Lion’ installer app located in Applications folder to another folder elsewhere because the installer app in the Applications folder will be automatically deleted after upgrading. Once it is downloaded, do not continue with the installation step because it will delete the installer file. You can buy and download the OS X Mountain Lion from App Store to upgrade your older Mac OS X version.

Install mountain lion from usb