This tips will come in handy when you are about to install a Mac OS, either Leopard or Snow Leopard on a Mac without the original disc and or with the DVD/Super Drive is out-of-order.


  • You can’t use the disc that come with a certain model of a Mac and install it in another model. You will get an error message – “Mac OS cannot be installed on this computer”. But you can use the retail version of the Mac OS – The one that you buy separately from any computer store.

Figure 1 – Mac OS Cannot be installed on this computer.

  • Don’t use Transmac to restore DMG to a USB/External HDD; you won’t be able to install the OS X. There will be No Entry logo when you boot from the USB/External HDD – it means that the restoration is not complete, I have tested on 2 different DMG files, and I still got the same error. There’s no way to restore the DMG file from Windows machine.

Figure 2 – Apple No Entry Logo When Booting.

Boot a Mac OS X (Leopard or Snow Leopard) using flash drive or external HD
-Step 1-7 = to format the USB/HDD
-Step 8-10 = install the OS to the USB/HDD  

  1. You need a DMG file for a OSX or the disk itself
  2. Plugin the external drive. (Flash drive or hard disk)
  3. Open up Disk Utility.
  4. Select the USB/External HDD – Choose partition.
  5. Once inside the Partition – Select 1 Partition, choose format as Mac OS Extended (Journaled) then click on Option.

Figure 3 – 1 Partition then Option

  1. Select GUID Partition Table – Select OK, later on the next window, select Apply. This will format your external drive (to prepare for the DMG restoration to the external drive)
  2. The formatting will take a while. Click on restore once it is finished.
  3. Drag the DMG, or the Leopard / Snow Leopard DVD to the Source field. Drag the USB to the Destination field. Then click restore.

Figure 4 – Source and Destination

  1. The process will take approximately around 20-30 minutes.
  2. After restoration, eject the disk. Restart the Mac, hold the OPT key when it boot – the USB icon will appear. Select it and follow the on-screen instruction to install the OS.

Credits :
Some picture and guides are from Maciverse