Guide: Multibooting UEFI on Separate Drives

[Going Bald]

I am attempting to install Win10 on a separate SSD in my system.

I followed the instructions exactly. But, after selecting the unallocated space in windows install and clicking continue, it stops with an error that tells me that it "cannot prepare the system for reboot" ... I cannot get past this point.

Disconnect or disable the port(s) where your other drive(s) are connected.

 

[HackinMax]

Disconnect or disable the port(s) where your other drive(s) are connected.

Thanks for the reality check. <facepalm> I should have known to try that.
I am desperately trying to avoid having to disassemble anything as the drives are UNDER the graphics card and another blocked by the CPU cooler tower (M.2 NVMe slots). It never occurred to me to just go into BIOS and disable the darned things.

 

[HackinMax]

Well, I just learned that PCIe M.2 slots cannot be disabled in BIOS. Makes sense I guess.
So, I had to tear it down, remove all NVMe drives except the one I wanted to install windows on... Put the rest of the parts back together... install Windows 10... tear it down again... reinstall the other NVMe drives...put it back together.

needless to say, that was a monumental PitB :-/

Anyway, @Going Bald was right.(Thanks for the nudge) Getting those other drives out of the way was the only way to install Win10 in this case. When will MS decide to become multiboot aware?

 

[Going Bald]

Well, I just learned that PCIe M.2 slots cannot be disabled in BIOS. Makes sense I guess.
So, I had to tear it down, remove all NVMe drives except the one I wanted to install windows on... Put the rest of the parts back together... install Windows 10... tear it down again... reinstall the other NVMe drives...put it back together.

needless to say, that was a monumental PitB :-/

Anyway, @Going Bald was right.(Thanks for the nudge) Getting those other drives out of the way was the only way to install Win10 in this case. When will MS decide to become multiboot aware?

It is not that MS is not multiboot aware - they just do not care.

 

[HackinMax]

It is not that MS is not multiboot aware - they just do not care.

So true.

 

[zell180]

Hi, mojave works perfect on my HP 340 G4. I've bought and SSD 2.5 to install windows 10 on it. Before this operation i've:
- formatted ssd from mojave
- disconnected the m.2 ssd where mojave is installed
- delete hfs partition and installed windows 10 on that space
- reconnected m.2 ssd.

When i restart the notebook clover stuck on "Welcome to Clover 7401 .... scan entries ...." why?

 

[ConmanCamaro]

I have High Sierra installed and set up on one m.2 nvme drive. I removed the drive and inserted a another m.2 nvme to install Windows 10 Education(I have a free product key). I only have a MacBook air(that is why I'm building this for school) so I created a windows 10 iso boot usb with bootcamp. Can I now just follow the steps "For win10"?

And will the Windows boot usb work correctly? Or do I need to use rufus and a VM to create a bootable usb drive?

 

[Going Bald]

I have High Sierra installed and set up on one m.2 nvme drive. I removed the drive and inserted a another m.2 nvme to install Windows 10 Education(I have a free product key). I only have a MacBook air(that is why I'm building this for school) so I created a windows 10 iso boot usb with bootcamp. Can I now just follow the steps "For win10"?

And will the Windows boot usb work correctly? Or do I need to use rufus and a VM to create a bootable usb drive?

It should work OK, assuming you got the UEFI installer on the USB as well as the Legacy installer. Try disabling the CSM in the BIOS/UEFI before installing Win10 to force the UEFI installation.

 

[ConmanCamaro]

This may seem like a dumb question I'm new to the windows world, but how do I tell if my USB has both the UEFI and Legacy installers? This is what it shows when I plug in and open my Win10 USB.

 

[ConmanCamaro]

I tried disabling CSM, but then the m.2 drive is not found in bios or the install. I enable CSM and "boot off storage device" to "UEFI Drive First". I created the GUID Mac OS Extended journaled partition with disk utility on the new m.2 drive. When I boot to the UEFI: windows USB it never gives me the option of "Custom Install" and just tries to install(seems really odd). Then it popped up with "Windows cannot locate the disk and partition specified in the unattended answer file's <ImageInatall> setting. Make sure the setting references a valid partition and restart the installation."

I have no I idea what to do with this, please help!
Only thing I can think is it is because I am trying to install Windows 10 Education??