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MP 1,1-5,1 Solved: Mac Pro 5,1 Windows 10 Install Help

quiet-cacophony

macrumors newbie
Original poster
Apr 26, 2020
9
4
I'm currently rebuilding a Mac Pro 5.1. Currently a 2x 8 core with 64GB RAM, it'll become a 2x 6 core shortly... Once I have a metal-capable GPU I'll be updating to Mojave.

For now all is going well on the OS X side of things: currently at 10.13.6 no problem and running just fine.

Where things are problematic is on the Windows side. I installed the latest Win 10 build available as an ISO from the Microsoft site. All goes well, until after I've booted. Windows Update seems hellbent on downloading and installing stuff regardless of whether I want it. It doesn't appear possible to selectively install updates...

Once I reboot the system (after it's been running after initial install for three hours...) it begins installing additional updates, even if I have clicked the defer updates option. After this, the machine fails to boot into Win. The blue Windows flag screen shows, then when it tries to go to log in screen, it shuts down the computer pretty gracefully before starting up again. I can boot into safe mode but can't for the life of me find the service or update that is causing the issue.

Any ideas?
 

quiet-cacophony

macrumors newbie
Original poster
Apr 26, 2020
9
4
Could the root of my problem be that I've inadvertently installed an EFI version of Win 10? I'd go to Legacy but who knows if I can find a DVD...
 
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jvlfilms

macrumors regular
Dec 11, 2007
179
97
Staten Island, NY
I recently did a full install of Windows 10 but I used a guide here on doing it with my RX 580. The process should be the same with the exception of being able to see the boot screen. These older cMPs are very finicky when it comes to drivers and can be problematic when switching to an APFS drive so just be on the lookout.


But unless you plan on using OpenCore, I’d highly suggest installing Windows in legacy mode.
 
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quiet-cacophony

macrumors newbie
Original poster
Apr 26, 2020
9
4

But unless you plan on using OpenCore, I’d highly suggest installing Windows in legacy mode.

Thanks for the reply. I never intended to install in EFI mode. I'd always intended to use Legacy / MBR, but unfortunately I failed to appreciate/understand that Mac Pro 5.1 does not support booting from a USB disk into Legacy mode. That is the underlying reason for the sentence in step one of the instructions you posted "[N.B. Do NOT replace the DVD by USB installer. It won't work]".

Unfortunately I didn't realise this before I started my journey. Now understanding this, and not having a DVD to burn (I ordered some from Amazon but I'm also impatient!) I was determined to make it work. I'm pleased to say I am now up and running smoothly. Here's how I did it:

  1. This will require:
    1. a running Windows computer or VM
    2. A SATA drive (I had mine in a USB caddy during creation, you can also do this internally)
  2. Download the Windows 10 ISO from Microsoft
  3. Download Rufus and launch
  4. When Rufus is running, press Alt+F. This will allow your external drive to be found. If you don't have a caddy, you can install the drive internally to the PC and use Ctrl+Alt+F to find internal drives too. Select the drive you want to create your Windows installer onto.
  5. Select your Windows 10 ISO and configure Rufus to create a Legacy / MBR mode installer. Start.
  6. Once complete, remove your SATA drive which now contains the installer. Insert into a free SATA port on your Mac Pro backplane.
  7. Boot Mac Pro holding option. You should see your Windows Installer drive as a bootable option.
  8. Follow Windows installation process as usual and install boot camp drivers on boot. I used a combination of the Brigadier iMacPro1,1 method and the Boot Camp 5.1.5621 drivers from Apple's site. The iMac drivers didn't include the right Bluetooth controller or MagicMouse drivers.
  9. You may find on first boot of the fresh install that the partition Windows installed to is not detected by Mac boot screen, or alternatively it gets stuck with a message of "An operating system wasn't found" If this happens, we need to create the necessary boot files and set the partition to active using diskpart. Instructions for this can be found here: Windows support
Because this method is SATA Installer to SATA target, it is fast. I think the installation itself took about 15 mins or less. Definitely faster than USB 2 or DVD. It would have been faster still if my installer drive were SSD too.

Anyway I wasn't aware of anyone using an internal SATA drive for their installer so I thought this might be useful to someone. It's also much more likely you have an extra SATA drive around than DVDs these days.
 
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startergo

macrumors 68030
Sep 20, 2018
2,713
1,150
Boot Mac Pro holding option. You should see your Windows Installer drive as a bootable option.
What do you see here:

1 Press the Win + R keys to open Run, type msinfo32 into Run, and click/tap on OK to open System Information.

2 In the right pane of System Summary in System Information, see if the BIOS Mode item has a value of Legacy or UEFI. (see screenshots below)

Check if Windows 10 is using UEFI or Legacy BIOS-legacy_bios_msinfo32.jpg

Check if Windows 10 is using UEFI or Legacy BIOS-uefi_msinfo32.jpg


Do you see Windows in the start drive selection in OSX?
 
Comment

quiet-cacophony

macrumors newbie
Original poster
Apr 26, 2020
9
4
What do you see here:

1 Press the Win + R keys to open Run, type msinfo32 into Run, and click/tap on OK to open System Information.

2 In the right pane of System Summary in System Information, see if the BIOS Mode item has a value of Legacy or UEFI. (see screenshots below)

Do you see Windows in the start drive selection in OSX?

It shows Legacy.

Yes I see Windows in Startup Drive (but I also saw it there when I accidentally installed EFI - It would just fail to boot into it if I selected it from OS X and if I did boot into it, after Windows Updates it just crashed out)

To clarify: I'm fully up and running now. Hopefully my internal disk install instructions are useful to someone.
 
Comment

quiet-cacophony

macrumors newbie
Original poster
Apr 26, 2020
9
4
Sorry for causing confusion. In my third post of the thread I wrote “I'm pleased to say I am now up and running smoothly. Here's how I did it:”

Basically I created a legacy mode installer on a SATA drive and ran it internally.
 
Comment

Muscovite

macrumors newbie
Apr 19, 2020
22
6
Thanks for the reply. I never intended to install in EFI mode. I'd always intended to use Legacy / MBR, but unfortunately I failed to appreciate/understand that Mac Pro 5.1 does not support booting from a USB disk into Legacy mode. That is the underlying reason for the sentence in step one of the instructions you posted "[N.B. Do NOT replace the DVD by USB installer. It won't work]".

Unfortunately I didn't realise this before I started my journey. Now understanding this, and not having a DVD to burn (I ordered some from Amazon but I'm also impatient!) I was determined to make it work. I'm pleased to say I am now up and running smoothly. Here's how I did it:

  1. This will require:
    1. a running Windows computer or VM
    2. A SATA drive (I had mine in a USB caddy during creation, you can also do this internally)
  2. Download the Windows 10 ISO from Microsoft
  3. Download Rufus and launch
  4. When Rufus is running, press Alt+F. This will allow your external drive to be found. If you don't have a caddy, you can install the drive internally to the PC and use Ctrl+Alt+F to find internal drives too. Select the drive you want to create your Windows installer onto.
  5. Select your Windows 10 ISO and configure Rufus to create a Legacy / MBR mode installer. Start.
  6. Once complete, remove your SATA drive which now contains the installer. Insert into a free SATA port on your Mac Pro backplane.
  7. Boot Mac Pro holding option. You should see your Windows Installer drive as a bootable option.
  8. Follow Windows installation process as usual and install boot camp drivers on boot. I used a combination of the Brigadier iMacPro1,1 method and the Boot Camp 5.1.5621 drivers from Apple's site. The iMac drivers didn't include the right Bluetooth controller or MagicMouse drivers.
  9. You may find on first boot of the fresh install that the partition Windows installed to is not detected by Mac boot screen, or alternatively it gets stuck with a message of "An operating system wasn't found" If this happens, we need to create the necessary boot files and set the partition to active using diskpart. Instructions for this can be found here: Windows support
Because this method is SATA Installer to SATA target, it is fast. I think the installation itself took about 15 mins or less. Definitely faster than USB 2 or DVD. It would have been faster still if my installer drive were SSD too.

Anyway I wasn't aware of anyone using an internal SATA drive for their installer so I thought this might be useful to someone. It's also much more likely you have an extra SATA drive around than DVDs these days.
The only method that worked for me. I now have EFI Windows with Open Core. I was also pleasantly surprised that the installer installed Windows to the very same drive. I was under the wrong impression that like usb, there’s the device with the installer, and the target drive.
 
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