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Dual Boot Guide Using a Single Hard Drive - OS X/Win 7


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Many people are confused or have problems creating a Dual Boot system on their machines. There is really a simple way of accomplishing this. The following is a guide for a basic dual boot system using OS X and Windows 7 (Windows 8 or 8.1 can be used, Linux requires a different procedure). Obviously, you will need to create a myHack installer for the model you are installing on, have access to a Windows disk and have a key to activate it. A hard drive of 120GB or larger is recommended, but smaller drives will work (with limited space for Apps and updates). It is recommended that you choose to boot with a one time boot menu, choosing your myHack USB as the boot device, but in BIOS set the device order to whatever media you are using to install Windows (disk or USB - this can be changed later, it's easier for now). Remember to set your BIOS to AHCI prior to getting started, and remember to revert the boot priority order back when you are done. Let's get started:

Boot into your installer and choose to use Disk Utility.
In the left side of Disk Utility choose the hard drive your will be partitioning/formatting.
Choose the Partition Tab.
Under Volume Scheme, choose to separate your drive into 2 partitions. These can be virtually any size (20GB or larger is recommended to allow for updates, larger is better).
Click on the Options button, choose GUID partition table, then click OK.
In the Windows that shows the partitions, choose the first one (should be Untitled 1). On the right, name it as you please (this will be you OS X partition, so name it something you will remember as being OS X), and format it as Mac OS Extended (Journaled). Next, click on the second partition (Aptly named Untitled 2), name it as you please (this will obviously be the Windows partition, it can be renamed later) and format it as MSDOS (FAT). Now click the Apply button, and when completed, close Disk Utility. 
Place your Windows Disk or USB into the system and reboot your system.

We will now be installing Windows.
The Windows media will initiate the boot process.
You will need to approve the Windows License agreement.
At the What Type of Installation Do You Want screen, choose Custom.
You will come to a screen (Where Do You Want To Install Windows) showing four entries, Disk 0, Partition 1 - 200MB, Disk 0, Partition 2 - (Your OS X partition, whatever size you chose), Disk 0, Unallocated              space, and Partion 3 - Windows (whatever size you chose)
Choose to install to Partition 3 - Windows, then click on Drive Options, choose Format, then OK in the box that warns you of the perils of formatting. This will change the format from MSDOS(Fat) to NTFS (needed to  

  install Windows).

Now Click Next to start you Windows installation. Install, add name, password (if desired) and license.
NOTE: If your Windows installation Media does not contain SP1, it is recommended that you update to SP1 prior to installing OS X, as you will likely encounter problems updating to SP1 if OS X is already installed.

You can now install OS X to Partition 2, using your myHack installer, with the bootpack and the method recommended for your model. 

It is recommended to update both partitions, and after updating the OS X partition and adding any Apps, run a myFix (Full version).  

If everything went well, you should boot into the Chameleon screen and have the option of which OS to boot into by using the arrow buttons to the right of the keyboard and the Enter key.



You will notice the Chameleon bootloader gives you a certain amount of time to choose Windows. By default, OS X will boot if Windows is not chosen in time. You have two options - you can adjust the time allotted to choose, or you can "freeze" that option to give you an unlimited amount of time to do so. In your OS X partition's Extra there resides a org.Chameleon.boot.plist. In there is a listing which says:




By using Text Edit and changing the number (in between the string notations), you can slow down or speed up the amount of time you have to make your choice (lower numbers give you less time to make the choice, higher numbers give you more time).

 Timeout                    Change Timeout to Instant Menu         Instant Menu
  5                             And the number to Yes                     Yes

Or to stop the process until you choose, you can change both, changing Timeout (between the key notations) to Instant Menu (A space between words and capital I and M), and the number between the string notations to Yes (with a capital Y). This will take affect next boot.        


You will notice that at the Chameleon screen your Windows drive is labeled Windows NTFS. You can change that by booting into Windows, click on the start menu, click on computer, then right click on HARD DISK DRIVES, then rename. Your drive will be highlighted and allow you to change the name. This too will take affect on the next reboot


You will notice that, even after changing them, Windows and OS X will show different times. This has to do with the way each configures the time. To make them both display the same time, you need to boot into windows, click on the start menu and enter regedit in the box, this will allow you to open the registry editor, which will allow you to make the necessary edits to co-ordinate the time between both OS's. Click Yes, then click the HKEY_LOCAL_MACHINE entry, then click on the SYSTEM entry, then CurrentControlSet entry, then the Control entry, then the TimeZoneInformation entry. On the right side, right click the white area anywhere under the TimeZoneKeyName entry and a box saying "New" will open. Move the cursor over the New box and a key list will open. If using a 32bit system, click on the DWORD (32-bit) Value, If using a 64bit system, click on the QWORD (64-bit) Value. At the bottom of the previous list, a new entry will appear with "New Value #1" in a box. Leaving it highlighted, type RealTimeIsUniversal in the box, with no spaces and the letters R,T I & U capitalized, then hit enter. Then click on the RealTimeIsUniversal entry and a box will open allowing you to Edit the QWORD or DWORD. Change the highlighted value from 0 to 1. Close out of the Registry Editor and after booting into both operation systems you will find both times are identical.

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Error message occurs in Windows after you change the SATA mode to AHCI/RAID in bios for the boot drive.

I have set up multiple dual boot systems using this method and myHack and as long as the BIOS is configured as AHCI prior to the installation of Windows, I have never come across this error. Additionally, when selling a previously hacked machine, I have reverted it back to Windows per a customers request, and have forgotten to revert BIOS to SATA and not received this message. Perhaps I am wrong, but the link seems to indicate the issue occurring if the BIOS change is made after installation of Windows 7 or Vista.

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yeah this is just a precaution in case they installed windows without setting AHCI mode first. like if resetting bios to defaults first and not setting sata mode after. you can revert sata mode back to IDE edit the registry for windows and then switch back to AHCI mode.

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