OS X Mavericks 10.9.4 bootable USB (DMG File) (13E28) Use the "Restore" option in Disk Utility to write it down on a USB-stick. How Format Your USB Flash Drive 1. Insert the USB flash drive into your Mac’s USB port. 2. Launch Disk Utility, located at /Applications/Utilities/. 3. In the list of drives attached to your Mac, select the USB flash drive device. In my case, it’s called 14.9 GB SanDisk Cruzer Media. 4. Click the ‘Partition’ tab. 5. Select ‘1 Partition’ from the Volume Scheme dropdown menu. 6. Enter a descriptive name for your flash drive; I chose "USB Install Drive" 7. Select Mac OS X Extended (Journaled) from the Format dropdown menu. 8. Click the ‘Options’ button. 9. Select ‘GUID Partition Table’ from the list of available partition schemes. 10. Click ‘OK. Now the USB flash drive is prepared you can Restore "OS X Base System.dmg" to your flash drive. 1. Click on "Restore" in the Disk Utility window. 2. Drag "OS X Base System.dmg" to "Source" 3. Drag the usb flash drive (in my case "USB Install Drive") to "Destination" 4. Click "Restore" en enter your system password. 5. Done.
1. Restart the machine and go to Recovery Mode (Kepp Press Command + R until logo appears during startup)
2. Go To disk utility and change the Startup Disk form the Menu
3. Select the "USB Install Drive" and Restart
4. It will start the installation from the bootable disk