Boot Windows on GPT disk with BIOS-only computer

[Tberdy]

As everybody knows, there are two majors partition scheme on PC : MBR and GPT. GPT has many more advantage than MBR, but I won't describe them here. GPT is used on all the Intel Mac by default and if you want to use MBR for your OS X install you'll have to patch your install. The best way is therefore to use GPT partition scheme. But if your computer doesn't have UEFI (BIOS only), some Windows editions like Windows 8/8.1 will refuse to install on GPT : because of Microsoft policy, only UEFI computer can use GPT as system drive.

 

 

EDIT : Before following this tutotrial, try a standard install ! This worked for Hervé.

 

 

Many peoples bypass this by creating an hybrid partition scheme GPT/MBR which consists of using GPT partition scheme with an MBR boot sector to start the windows bootloader. But this partition scheme is very dirty : you can read this article from Rod Smith which will convince you to not use it.
http://www.rodsbooks.com/gdisk/hybrid.html
 
An other solution is to use the standard GPT (which is part of uefi specs) and emulate the UEFI bootloader. Tianocore/DUET is often used in all the tutoral I've seen ; but it's a little long to install and it won't work on all computer, according to Rod Smith (http://www.rodsbooks.com/bios2uefi/index.html). In the hackintosh world we have the best  : Clover EFI bootloader.
Clover EFI is a fork of DUET which emulate Apple EFI on PC to boot OS X, but it can emulate UEFI too. 
 
Requirements :
 
- PC with a BIOS only  (no UEFI)
- a free HDD
 
What you can expect of this tuto :
 
- multi OS setup between EFI and legacy OS 
- a clean pure GPT partition table 
- Clover EFI bootloader
- a more "vanilla" OS X install
 
At this time, I do all my tests on a ThinkPad T410 with a BIOS and Windows 8.1 and I have a clean Windows install on GPT. I'm booting from an USB key with Clover installed on it. I just have to move Clover from the USB to the EFI part of my GPT disk and install OS X (I received it two days ago)
 
I will complete this tuto with more informations and screen later because I don't have a lot of time (Baccalauréat is coming for me...) but you can follow this short guide :
 
1 - Partition your hard drive with GPT ! you will lose your data ! You can use the program you want 
 
2- Create EFI partition : I used a Diskpart on a windows to go key to make sure windows detect the part is an EFI one 
 
3 - Create an MSR partition using diskpart (windows)
 
4 - Create the root file system (NTFS) of your windows install. Keep enough space at the end of the disk for OS X and/or Linux.
 
5- Prepare a Clover EFI boot key. There are a lot of tuto explaining this. 
 
6- Prepare an windows install usb install media. Clover didn't see the windows DVD for me, but it may work for some people. 
 
7 - Boot from the Clover USB and select your windows install media. Install windows on the partition you've made previously.
 
! It doesn't work for me ! The install failed. It worked with DUET so maybe it can work with Clover.... See 7bis
 
7bis - From a windows OS (I used my Windows To GO key) : use the the imagex command to expand a windows ISO on your Windows partition
 
imagex.exe /apply F:\sources\install.wim 1 G:\ 
F: is the mounted iso and G: the windows partition. 
Then configure the windows bootloader 
bcdboot.exe G:\windows /s H: /f UEFI 
G: is the windows partition and H: the EFI partition of your disk 
For these steps you will need to install the windows ADK.
 
8 - remove your windows install media and reboot to clover usb. Then select Microsoft EFI from the Clover menu. That's all : you have a working install of windows with pure GPT and BIOS 
But you still need to use your clover key each time you want to boot...
 
9 - Install OS X using Clover or Chamelon 
 
10 - In OS X mount EFI part and install clover on it WITHOUT formatting the EFI part. You must change the clover installation options to install the boot sectors. See the clover doc.
 
Now you can boot Windows without key, just with selecting Microsoft EFI in Clover Menu 
For the people who use Clover to install OS X you can boot OS X too. 
 
11 - Chameleon lovers (untested) 
Install Chameleon on the OS X partition WITHOUT erasing the main boot sector 
Use fdisk if you are not sure : install the PBR and chameleon only.
Then configure Clover to allow booting from legacy OS 
Boot your computer and select your OS X partition in Clover
You may arrive to the Chamelon Menu.
You are done 
 
 
BIOS --> CLOVER EFI --> Windows Boot Manager (UEFI)
BIOS --> CLOVER EFI --> OS X (Apple EFI emulate by Clover)
or
BIOS --> CLOVER EFI --> Chameleon --> OS X (Apple EFI emulate by Chamelon)
 
This guide is still in BETA and not complete so no complain 
If you have questions, I would be happy to answer if I can.

 

 

 

 

Extra Guide (mainly for chameleon users or people who can't make Clover to work on their computer)

 

Thanks to milindsmart we have others solutions to boot windows installed on pure GPT.

 

1) Use a boot drive in MBR. 

Windows is installed on pure GPT but windows boot files are located on the MBR drive. Windows is loaded in BIOS and not UEFI emulation like with Clover

See detailed topic by milindsmart itself : http://www.sevenforums.com/installation-setup/320700-boot-windows-7-8-gpt-bios-system-no-hybrid-mbrs-duet.html

 

2) Use a virtual drive image

Bootloader loads a disk image (with MBR) which contains Windows Boot Files 

No need for multiple drives 

See here for infos : http://reboot.pro/topic/19516-hack-bootmgr-to-boot-windows-in-bios-to-gpt/page-5?do=findComment&comment=187175

[Hervé]

You are somehow incorrect regarding installing Windows on a GPT partitioned disk in the sense that it is not limited to UEFI computers only. There's no problem doing that at all on bog standard older computers running "legacy" BIOS only. This works for Win7 at least, I can't speak for older OS like XP or Vista.

 

That is exactly what I have on one of my Latitude D630:

 

This HDD was originally partitioned through Disk Utility, having booted a myHack USB Lion installer with its default Chameleon bootloader. Win7 was installed after OS X Lion. The Win7 partition was initially formatted FAT in Disk Utility and subsequently reformatted NTFS by the Windows installer. There was no involvement of Clover or any other fancy tool, just our good old regular Chameleon and myHack installer.

[Tberdy]

Oh I've maybe made a mistake but when I try to install Windows on my GPT disk, the installer tells me GPT isn't supported by legacy BIOS

[bobdamnit]

Windows 7 will install on a GPT disk with "legacy" BIOS, however Windows 8/8.1 will not on "legacy" BIOS. It must be installed on MBR with legacy BIOS. Windows 8/8.1 can only be installed GPT with a UEFI BIOS.

 

So, technically, this tutorial by Tberdy is very accurate and helpful for those trying to install Windows 8/8.1 on a "legacy" BIOS machine.

 

Source: http://technet.microsoft.com/en-us/library/dn336946.aspx

[Hervé]

I've not bothered to experience with Win8 so your precision is very useful indeed. The tuto should be refined to that effect.

[Tberdy]

I've tried again to install Windows 7 on my ThinkPad with GPT and Genuine Windows Install DVD : no way.

(Sorry for the French Screen ; it's my genuine DVD)

[pokenguyen]

All Windows Legacy (even 7, 8, 8.1) can install to MBR and GPT disk, if that GPT disk is GPT/Hybrid MBR. To convert from Pure GPT to GPT/Hybrid MBR, use Disk Utility in OS X to create a FAT 32 partition, it will change the disk partition table. Or you can use gdisk in a USB Live Linux (for example Ubuntu), go to terminal to install gdisk, then create a Hybrid MBR partition table.

 

In general, there are two types of Windows install:

 

Windows Legacy:

- Only install on MBR or GPT/Hybrid MBR.

- Can boot from Chameleon/Clover.

- The USB install will be formatted as NTFS.

 

Windows UEFI:

- Only install on GPT/Protective MBR

- Can boot from Clover.

- The USB install will be formatted as FAT32.

[Hervé]

I've tried again to install Windows 7 on my ThinkPad with GPT and Genuine Windows Install DVD : no way.

(Sorry for the French Screen ; it's my genuine DVD)

Was the Win7 destination partition formatted FAT at all, prior to booting the Windows installation DVD? That is necessary.

[Tberdy]

You're right Hervé, my Windows 7 part was not formatted in FAT by OS X disk utility. That's why it worked for you and not for me : your HDD is on GPT/Hybrid but not mine. 

BTW I understood my main PC (Asus N550JV) was on GPT/hybrid (disk utility), which is useless because it has an UEFI BIOS . Thanks pokenguyen.

 

Does someone now how to revert to pure GPT ?

[pokenguyen]

You're right Hervé, my Windows 7 part was not formatted in FAT by OS X disk utility. That's why it worked for you and not for me : your HDD is on GPT/Hybrid but not mine. 

BTW I understood my main PC (Asus N550JV) was on GPT/hybrid (disk utility), which is useless because it has an UEFI BIOS . Thanks pokenguyen.

 

Does someone now how to revert to pure GPT ?

The only way is using a linux live usb, install gdisk and use it to convert to GPT/Protective MBR (Pure GPT). If you turn off UEFI and enable Legacy BIOS, you can still use Windows Legacy/Hybrid MBR on your laptop.