Windows 10 install trouble map 2012 Catalina

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Level 1

9 points

Windows 10 install trouble map 2012 Catalina

Hi all how are you doing?

Here are my MacBook specs:

And here is my storage arrangement:

I am trying to install Windows 10 via bootcamp. I watched several videos beforehand and followed the instructions exactly as given by bootcamp.

Bootcamp created the partition for Windows (100gb).

When my MB restarted itself I was confronted with the black screen and blinking cursor.

I restarted holding alt key and saw 3 available disks to choose: My mac ssd, EFI (something) and Windows.

Clicking into windows drive leads to the black screen. Entering EFI leads to windows set up but it is blocked by "partitioned disk is MBR and is not formatted to GPT" or some such wording.

After several hours of reading, downloading disk and running:

sudo gdisk /dev/disk0

I am still none the wiser.

This is what I saw when I ran the above command:

Found valid GPT with protective MBR; using GPT.

I have a full back up from yesterday.

One thing I read was using disk to convert from MBR to GPT. I got as far as executing that command but got nervous when a warning told me it would erase the entire drive. Plus I thought it was already using GPT?

Can I format JUST the partition I have created for Windows instead of the whole drive?

If the whole process goes belly up and i have to restore from my back up do I restore to the entire 500gb drive or the 400gb MAC OSX partition?

Many many thanks

Posted on Nov 24, 2020 2:05 AM

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Answer 1

Loner T

Level 9

59,471 points

Nov 25, 2020 8:36 AM in response to pegdrums

Your 2012 Mac only supports legacy BIOS mode installation.

If you use the Windows icon from the USB Installer, this is the legacy BIOS installer and requires a MBR on the main bay disk.
If you use the EFI Boot icon, this is the UEFI installer, and your Audio (and some other hardware) will not work properly.
The installer may start, but it is the point at which you will start seeing issues. The partition creation is a macOS BCA function, which assumes that your configuration will support partitioning. Once the installer comes up, there is no macOS.

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Answer 2

Loner T

Level 9

59,471 points

Nov 26, 2020 7:41 AM in response to pegdrums

On a 2012 (and older Macs), there is an overlay that is used to make the disk behave like an older disk partitioning scheme. This old scheme is called Master Boot Record (MBR). The underlying layer is still a Guid Partition Table (GPT). With this overlay, if you use EFI boot, you will see "partitioned disk is MBR and is not formatted to GPT" error. If you remove this overlay, the underlying GPT is exposed to the installer. On your specific model, GPT should not exposed.

If you choose the Windows icon and you get a black screen, there are two possible reasons for the 'black' screen.

The W10 ISO is a W10 1903 or newer ISO which does not support the Intel GPU on the 2012 model, or,
You are using a USB3 Flash drive. You will need a USB2 Flash drive instead.

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Answer 3

Loner T

Level 9

59,471 points

Nov 27, 2020 6:31 AM in response to pegdrums

pegdrums wrote:

If I drag that windows support folder into the new windows partition and drop it there I should be able to install them when in windows right?

You cannot write to the Windows partition from the macOS side, unless you use third-party software. The safer method is to use a USB2 Flash drive, run BC Assistant -> Action -> Download and get the drivers on the USB2 drive, reboot into Windows and run setup.exe from the Bootcamp folder on the USB2.

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Answer 4

Loner T

Level 9

59,471 points

Nov 24, 2020 8:44 AM in response to pegdrums

You have two physical drives, which is not supported. If you must have both, you will need to disconnect the disk in the Optibay from the disk end (not the Logic Board end), install Windows on the main bay disk, and windows must stay on the main bay disk. Once Windows is fully functional, you can reconnect the Optibay disk. Be aware, that Windows Repair using an external USB will not work properly, with both disks connected.

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Answer 5

pegdrums Author

Level 1

9 points

Nov 24, 2020 10:10 AM in response to Loner T

Thanks for your reply. I haven't read anything yet about having to disconnect the other drive. Interesting. Sounds like quite the faff just to install an O/S though.

I don't understand how bootcamp was happy to create the partition and the windows installer will start and get me so far.

Is there any alternative to this disconnect and reconnect option?

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Answer 6

pegdrums Author

Level 1

9 points

Nov 25, 2020 12:38 PM in response to Loner T

Thanks again for your time.

Please excuse my ignorance here as all I can do is read as much as possible and try to understand.....computer world has a LOT of acronyms which start to hurt my head.

Is your first point in your reply an option I can entertain to try and make this work or just telling me why it won't work?

Can I set up my ssd to be GUID compliant (or whatever) and have MBR on it?

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Answer 7

pegdrums Author

Level 1

9 points

Nov 26, 2020 11:13 AM in response to Loner T

Thanks again,

here is my iso version im trying to use: Win10_20H2_English_x64.iso

I was indeed using a usb 3 flash drive so will try pick up a usb 2 tomorrow.

I found a tutorial for installing to an external disk using VMware and Win to USB. It seemed to work really well, Windows was somewhat functional in the virtual machine environment but after trying to install to the external drive same black screen with blinking cursor appeared.

If the USB method doesn't work is there another workaround? i read about gdisk

It's not essential I get this to work but I'm doing an I.T course (comp TIA A+) and would like get familiar with Windows as I move through the course. Also I'm tenacious so now that I've started I have to see it through!!

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Answer 8

Loner T

Level 9

59,471 points

Nov 26, 2020 11:33 AM in response to pegdrums

Try to find an older W10 ISO from a reliable source. On the 2012 MBPs that I have, W10 was installed using W10 1511. W10 1809v2 was used on a 2014 iMac. Once you have the older W10 release installed, you should be able to Windows Update to get the newer releases. The transition through W10 1903 can be problematic, because it uses SysPrep which is notorious for failures.

pegdrums wrote:

Also I'm tenacious so now that I've started I have to see it through!!

Very 😎.

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Answer 9

pegdrums Author

Level 1

9 points

Nov 26, 2020 2:04 PM in response to Loner T

So....I found an older iso (Windows_10_Multi_(Home_Pro)_X64_English 1507) and that didn't work.

Tried to install a 32 bit version and it flat out wouldn't let me.

I could take some screenshots of any relevant bits that might help?

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Answer 10

pegdrums Author

Level 1

9 points

Nov 27, 2020 4:45 AM in response to pegdrums

Just tried it there on my break and it worked!! i did use a USB 2 key and the W 1507 iso (1511 downloaded as 32 bit even when file said 64 bit)

So it's up and running thank you so much.

No I just have to install the apple drivers/ Windows support folder that I had downloaded previously.....that's my next challenge!

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Answer 11

pegdrums Author

Level 1

9 points

Dec 2, 2020 7:31 AM in response to Loner T

Sorry for not getting back to you.

That worked a treat. It's up and running now and today I installed a whole pile of updates.

It's funny because I used Windows for donkeys years and going back to it now after 8 years on a mac it feels so clunky compared to OSX. Also it doesn't look very different visually to Windows 7, some stuff even reminds me of Windows 95. Stylistically is all. I'm sure plenty has changed and improved.

Thank you very much for all your help and hopefully someone else stumbles across this thread and it helps them in the future.

All the best

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