Note!: A clean install will erase all the contents and partition on your disk drive. Make sure you take back up of your important files before proceeding.
Download OS X Yosemite
- To do a clean install of OS X Yosemite, you’ll need a blank USB flash drive or External HDD that is at least 8GB in size.
You’ll also need to download OS X Yosemite onto your existing Mac.
Download OS X Yosemite from Apple Store.
You will be prompted to continue download, Click on Continue
- Provide your Apple ID and Password and click on Sign In
Erase USB/HDD Drive
- Open Disk Utility Application and Select your USB/HDD drive and click on the “Erase” tab.
- Select Mac OS Extended (Journaled) as the format type.
- Click the Erase button. This will take a few minutes, but will erase your USB/HDD drive will be erased and format it with the proper file system.
Download DiskMaker X
- Download DiskMaker X
- Once its downloaded, just install it.
Make Bootable USB/HDD Drive
Open DiskMaker X by pressing
Command ⌘ and space
Click on Yosemite(10.10)
We already downloaded OS X Yosemite, So click on Use this copy
Click on Another kind of disk
Make sure you choose right USB/HDD (Will be formated)
Make sure you selected right USB/HDD
Next step provide administrator password, click on Continue
- Its take some time to format selected USB/HDD drive.
Provide administrator password and click on OK
The installation may take a little time, so grab a cup of coffee and relax.
- We just make Bootable USB/HDD.
Boot from USB/HDD
- Start Mac Book and hold the
Alt/Optionkey on your keyboard as soon as you hear the Mac’s startup chime.
- After a few seconds, you’ll see all of the bootable devices appear on your screen.