[HOW-TO] Dual boot Windows and OS X from different Hard Drives
 

I figured since I posted this material in a different post in a reply recently, I'd throw this out there for people to use. Its an old method and can be found all over the net.

This method will use the Windows bootloader on the Windows-installed HD. (any other methods to do this can be added to in posts later)

The windows bootloader can be used to select (at pre-windows startup) which system to boot.

Copy the chain0 file from your OS X drive located at:
to your windows drive's root directory (ie. "C:\chain0")

Now boot into windows and add
to your Windows bootloader via many different methods. A few of the most commonly used methods are:

1) enable hidden files/folders and system files from the Folder Options menu. then navigate to C:\boot.ini to edit with the code above.
2) Right click on "My Computer" and select Porperties -> Advanced -> Startup and Recovery "Settings" and click "Edit" to add the code above.
3) Control Panel -> System (from classic view) -> follow method 2 from here.

Go into your BIOS and ensure that your Windows HD is the one that is selected to boot. When you turn the computer on, you should get a menu for

Windows
Mac OS X

You can choose either, and once you select and press enter, it should automatically boot into the desired OS. No other settings required. You can also change the default system to either drive using the same Windows bootloader.

if osx and win reside on different drives, one simply choose bootdrive with bios (f12 for me).
so no editing any bootfiles neccessary :)

Yes... but this isn't a really nice option... best to use a bootloader like easybcd, they are working about a 2.0 beta version booting from different drives and pc_efi.
News about it on this thread

This is a simple edit when using windows and OS X. There are a lot of other options out there but until the new chameleon version comes out, none are as simple to noobs.

What exact version of chameleon are we then waiting for?

I am looking for having a possibility to boot into Windows Vista x64 from chameleon, since OS X is on my first SATA Hdd and Vista is on the second SATA Hdd. Can someone hint me what to try? Fumbling around in BIOS everytime is not a nice option.

hi all, does anyone have another way for this ? i've tried this with boot0, chain0 boot.efi , but the osx won't load it keeps going back to the bootloader menu, i have osx 10.5.6 on 1 disk (sata) partitioned guid with chameleon 1.12 and win xp on another disk mbr also sata i'm running in ahci mode.

can anyone help me out

I can't copy the file! I found it in terminal, but I can't get to it with Finder.
What do I do? I'm going to try this from single mode while I'm waiting.

the way i do it is by just making my Mac HD the default(in BIOS) and using Chameleon to boot everything

yeah but with chameleon 1.0.11 it is not possible to see boot options ranging over many HDD's however with the new Chameleon 2 RC1 there is no need for messing around with files as it searches your whole system for bootable disks, over all your HDD's

Chameleon 2.0RC1 is coming along very nicely.

However, there is one issue that I ran into when using it to dual boot WinXP and Leopard on separate drives, so I thought I'd share the solution here.

Anyway, I installed RC1, and it gathered the information for all my bootable disks correctly, only upon reboot I'd select my WinXP NTFS partition and it would hang with a flashing cursor on a black screen.

Turns out that in order for WinXP to be dual-bootable in this fashion, it needs to be the selected boot drive in the BIOS... but to get to the Chameleon bootloader, the OSX drive must be selected as the boot drive in the BIOS. Quite the conundrum.

The solution turned out to be rather simple... make sure to include a small (or in my case, large) HFS+ partition on the same drive as your WinXP install, and install Chameleon to that drive. This satisfies the need for WinXP to be the default boot disk, and for Chameleon to control the boot process.

So to illustrate, my drive layout looks like this:
[DRIVE 1]: GUID - (600GB Leopard Install)
[DRIVE 2]: MBR - (100GB WinXP Install) - (350GB HFS+J Scratch Disk)

I installed Chameleon RC1 to the 350GB HFS+ partition on drive 2, and now it pops up as the 'default' disk in the chameleon bootloader screen, and the Leopard/WinXP disks are also both listed as bootable options. The nice thing is that since there is no bootable kernel on the scratch disk, Chameleon times out and defaults back to manual select mode, waiting for you to select which OS to boot from... so you can walk away from a reboot and not have to worry about being there to hit F12 at the appropriate moment.

Just my .02