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[HOW TO] Install OS X without CD/DVD drive

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A lot ultra-portable laptops do not have CD/DVD drives these days, and many people do not have externals. A possible solution is to install OS X from a USB drive if the BIOS is able to boot from a USB drive. Here is what you need:


1. An image of the install disk (usually a .iso file)

2. A USB drive big enough to hold the install disk image (4 GB or more)

3. Access to a computer running OS X


Here are the steps:


1. Put the install disk image onto the USB drive and bring it over to the OS X computer.


(Note: next 3 steps can be done using the restore function in Disk Utility)


2. Copy the image to the hard drive and then mount the copy (look at the mount location, it should be /Volumes/$Name of Install Disk Here$)

3. Open Disk Utility, choose the USB drive, go to Erase, and Erase with Mac OS Extended. (Note the name of the partition, I used MBR for this, but you can use GUID probably if you want)

4. Open terminal and run the following:

sudo cp -R /Volumes/$Name of Install Disk Here$/* /Volumes/$Name of USB Partition Here$/

(Be sure to insert the correct mount locations in place of $Name of Install Disk Here$ and $Name of USB Partition Here$)


5. Once copying has finished install Chameleon on the USB drive (by hand or with installer)


6. Now go back to you computer without a CD/DVD drive, set the BIOS to boot from the USB, boot from the USB and install.


Note, this method should also work with external hard drives. Also, if you are lucky, you can simplify steps 2-4 by using the Restore function is Disk Utility. Simply mount the install DVD, click on the USB drive, click restore, drag the mounted install image into source and the USB partition into destination an then run it (this may or may not work for everyone).


Anyway, hope this is helpful. Good luck.




If anyone cares, it should be possible to do this from Windows using a USB flash drive, or simply a partition on your HD and a boot-132 USB flash drive (partition is easier). I might add a guide for this later.

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Nice Guide.


There is a little software can do same things under Windows.


Leopard HD install helper v0.3(Win32), Install leopard from HD. Faster ! without DVD!


I have another idea :

step1. Use dd for win dump ISO to a Primary Partition of HD or USB stick

step2. Install Chameleon into that Primary Partition of HD or USB stick.



But there is a big problem: How to install Chameleon under windows?

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My iDeneb 1.3 has Chameleon pre-patched already (I think. It says so in the Darwin boot sequence). Do I have to put Chameleon again?


BTW, I have EasyBCD on the Vista x64 side of my partition. And I'm running Tiger on VMWare to do all the USB formatting and stuff.


Sorry, I'm a complete noob when it comes to booting things.

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Hi the.delro , Just use dd for win dump ISO to your USB stick , then try boot from the USB stick.

See it's works or NOT.


Use dd for win carefully , don't dump ISO to wrong disk.


use dd --list found device name of USB stick.


do ISO dump like this :

dd if=c:\iDeneb1.3.iso of=\\.\Volume{c18588c0-02e9-11d8-853f-00902758442b}  bs=1M


By the way : the ISO use cdboot(Chameleon bootloader cd version) boot up , when you dump ISO to Partition , I think that need boot(Chameleon bootloader hd version).


That is what I thought. Please report the result , I hope I am wrong.

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Thanks max22 and twilight.lee!


I finally installed 10.5.5!


My own guide:


This is perfect for people with:

a.) a PC that has a busted optical drive and the BIOS doesn't support external optical drive booting;

b.) a thumb drive or an external hard drive instead of a disk burner.


And of course, they don't have a Mac lying around.


(In case somebody else has to endure the same type of ordeal I faced. I nearly bricked 2 PCs!)



Compaq Presario C552US with 80GB HDD. Doesn't support external optical drive booting. Supports USB non-optical drive booting. Internal CD-RW drive is broken.


Transcend 15GB USB thumb drive. (A 5GB drive is the minimum for this particular distro)



Windows Vista Ultimate x64

VMWare Workstation 6.5

Daemon Tools x64 (VMWare's native .iso reader doesn't work with Mac-format images)


iDeneb v1.3 10.5.5


(An old copy) of a ready-to-use 10.4.10 VMWare appliance. Easily found, just look in Google.



1.) Install Tiger (or Leopard, though that's harder) in VMWare. Look elsewhere for a guide.

2.) Copy .iso to NTFS (FAT-32 if your distro is less than 4GB. OS X can read but not write to NTFS) formatted thumb drive then transfer the .iso to Virtual Machine.

3.) Mount .iso in VM.

4.) (In disk utility's partition tab) Format thumb drive to HFS+ Journaled. In settings make sure it's MBR.

5.) (In disk utility's restore tab) Drag and drop mounted .iso to the source box. Drag and drop mounted thumb drive to destination. Click restore.

6.) Restart PC. Make sure BIOS will boot into USB drive. Install!

[uPDATE]: If your PC can't see the USB drive, download OSX86 Tools, then install PC EFI v8 on your USB!


Notes: Personally, I had no trouble with the Darwin Bootloader (probably because iDeneb had Chameleon included). You may have to set the active partition in terminal in OS X or diskpart in Windows. I can easily pick between Vista and Leopard.

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To have the USB drive boot the ISO you will need chameleon (or PCEFI) in the MBR of the USB drive (as they are booted like external HDs i I am not mistaken). I think cdboot shouldn't work.

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