Force Win 10 Installer DVD to boot UEFI only?

[PianoPro]

My Objective - to force a Win 10 Installer DVD to boot in UEFI Mode on a 2010 Mac Pro without a boot screen

Holding the Option key while restarting a Win 10 Installer DVD produces two Installer boot choices on the Boot Manager Screen - UEFI or Windows (legacy-BIOS). Win 10 will automatically be installed to boot in the same mode chosen to boot the Installer.

But when a Mac Pro video card can’t produce a boot screen you can't choose. If you simply allow the DVD to boot automatically (by holding the C key while restarting) it ALWAYS boots in the legacy-BIOS mode. You also can't choose from the Startup Disk preferences pane. It only shows the Installer DVD with a single Windows icon, and that boots into legacy-BIOS mode.

I tried all sorts of versions of the Bless command from the terminal, but everything I tried to bless the EFI folder or EFI files only resulted in booting legacy-BIOS.

So I tried to modify the Win10 iso to create an installer DVD without any BIOS booting in hope it would then boot UEFI. According to the following Microsoft page it looked like removing the bootmgr file might do it, but the DVD would not boot at all when I removed the bootmgr file. I get a text message on the black startup screen that a boot manager could not be found, and then booting into an OS continues automatically.

https://docs.microsoft.com/en-us/pr...s/it-pro/windows-8.1-and-8/dn293283(v=win.10)​

If this is a frequent problem, you can remove the boot files for UEFI mode or BIOS mode to prevent the PC from booting in the wrong mode. If the PC firmware is set up to boot in the wrong mode, the media will immediately fail to boot, allowing you to immediately retry booting the PC into the correct mode.​

• Boot in UEFI mode: To prevent Windows PE from booting in BIOS mode, remove the bootmgr file on the root of the media.
• Boot in BIOS mode: To prevent Windows PE from booting in UEFI mode, remove the efi folder on the root of the media.

Does anyone have a solution to modify a Win 10 Installer DVD to force it to boot UEFI?

 

[h9826790]

You make it too complicated. As a general rule

DVD installer -> default Legacy mode

USB installer -> default UEFI mode

All you need is just make a bootable USB installer and Hold C to boot from it

 

[tsialex]

You make it too complicated. As a general rule

DVD installer -> default Legacy mode

USB installer -> default UEFI mode

All you need is just make a bootable USB installer and Hold C to boot from it

What is the magic to make Mac Pro firmware boot Windows installer from USB? Never got that working.

Apple even had a support article about this sometime ago, no Mac with DVD drive could boot Windows from USB.

 

[h9826790]

What is the magic to make Mac Pro firmware boot Windows installer from USB? Never got that working.

Apple even had a support article about this sometime ago, no Mac with DVD drive could boot Windows from USB.

Tested, can work.

I believe the trick is to get a "good" USB drive. Most of my old USB drive can't boot on cMP, but few newer one can do it.
[doublepost=1538954539][/doublepost]But I have absolute no idea how to pick the good one

 

[PianoPro]

Tested, can work.

I believe the trick is to get a "good" USB drive. Most of my old USB drive can't boot on cMP, but few newer one can do it.
[doublepost=1538954539][/doublepost]But I have absolute no idea how to pick the good one

I wish that worked for me but it doesn't. I didn't pull out all of my HD's and SSD's if that matters. Booting from USB drive never worked for me before I had an SSD in the lower optical drive slot either.

2010 Mac Pro, original DVD drive, RX-560 video card, BT dongle, 12 GB RAM, 2 SSD's with Mojave, HS. 3 HD's with HS, Win 10. Otherwise stock.

 

[LightBulbFun]

What is the magic to make Mac Pro firmware boot Windows installer from USB? Never got that working.

Apple even had a support article about this sometime ago, no Mac with DVD drive could boot Windows from USB.

the Mac Pro 1,1-5,1 from the Boot picker cant Boot legacy BIOS OSs from USB devices

however it can of course load EFI applications/OSs off of USB, so if you make a UEFI Windows USB stick then that will show up just fine in the boot picker (since all the Boot picker is doing, is loading the .efi windows boot loader application, then the windows Boot loader does it thing loading the kernel etc)

 

[PianoPro]

the Mac Pro 1,1-5,1 from the Boot picker cant Boot legacy BIOS OSs from USB devices

however it can of course load EFI applications/OSs off of USB, so if you make a UEFI Windows USB stick then that will show up just fine in the boot picker (since all the Boot picker is doing, is loading the .efi windows boot loader application, then the windows Boot loader does it thing loading the kernel etc)

What does "Boot Picker" refer to? That's not a common Mac term?

Are you referring to the Boot Manager screen you get when you hold the Option key during restart? Yes, we know a USB drive shows up there just fine, but the point is I don't have that screen with the RX-580 video card.

Or does "Boot Picker" refer to the Startup Disk panel from System Preferences? A USB drive does not show up there at all.

So none of that helps what I want to do.

 

[monkeybagel]

What is the magic to make Mac Pro firmware boot Windows installer from USB? Never got that working.

Apple even had a support article about this sometime ago, no Mac with DVD drive could boot Windows from USB.

It works fine on Windows 8.x and newer. Just make the USB drive formatted FAT32 and ensure the EFI bootx64.efi file is in the correct location, hold Option while booting and select EFI Boot.

Since the install.wim file in some builds of Windows 10 and Windows Server exceed the FAT32 size limitation, the utility Rufus has a workaround that will kickstart booting on a very small FAT32 partition it creates, loads a drivers for NTFS and the Windows installation files are actually on the NTFS partition working around the limitation.

 

[LightBulbFun]

What does "Boot Picker" refer to? That's not a common Mac term?

Are you referring to the Boot Manager screen you get when you hold the Option key during restart? Yes, we know a USB drive shows up there just fine, but the point is I don't have that screen with the RX-580 video card.

Or does "Boot Picker" refer to the Startup Disk panel from System Preferences? A USB drive does not show up there at all.

So none of that helps what I want to do.

I was mostly responding to @tsialex queries

however as for your issue

Boot picker refers to the Menu you get when you hold the Option key down on POST apple refers to it as such here for example https://support.apple.com/kb/DL1321?locale=en_US

since you have no Boot Screen because of your RX 580, even if you DID manage to boot the windows DVD in UEFI mode you wont get any picture as the windows PE environment uses the the machines Firmware frame buffer of which there is none in your case.

so the only way you would be able to do anything is to setup an unattended install.

or just drop in an EFI Video card for the installation of windows 10 then swap things out afterwords (which would also let you pick the EFI Boot option in the boot picker)

 

[PianoPro]

Boot picker refers to the Menu you get when you hold the Option key down on POST apple refers to it as such here for example https://support.apple.com/kb/DL1321?locale=en_US

Thanks for clarifying. I've always called that the Boot Manager screen, or just boot screen. But Boot Picker is fine too.

since you have no Boot Screen because of your RX 580, even if you DID manage to boot the windows DVD in UEFI mode you wont get any picture as the windows PE environment uses the the machines Firmware frame buffer of which there is none in your case.

so the only way you would be able to do anything is to setup an unattended install.

or just drop in an EFI Video card for the installation of windows 10 then swap things out afterwords (which would also let you pick the EFI Boot option in the boot picker)

OK, that's a surprise. I expected a UEFI boot from the Win DVD would drive my RX-560 (immaterial, but I mistyped 580 before) video card to produce the necessary images during the install process, as it does perfectly fine when doing a legacy-BIOS boot install from the DVD. If it doesn't, then there is no reason for me to create a UEFI-only DVD because I would have to use one of my old HD 5770 cards anyway, and then I'd use the "Boot Picker", as I've done before. I was just trying to avoid changing video cards for the 100th time if wanted to go back to a UEFI Win 10 installation again.

Thanks for the education!

 

[tsialex]

the Mac Pro 1,1-5,1 from the Boot picker cant Boot legacy BIOS OSs from USB devices

however it can of course load EFI applications/OSs off of USB, so if you make a UEFI Windows USB stick then that will show up just fine in the boot picker (since all the Boot picker is doing, is loading the .efi windows boot loader application, then the windows Boot loader does it thing loading the kernel etc)

My question was about Windows, I never got that working. I know that Mac Pro firmware can boot EFI from USB, it's the way I use rEFIt/rEFInd.
[doublepost=1538994910][/doublepost]I'll try creating the USB key with Rufus like @monkeybagel suggested.

 

[1151105]

hey tsialex, where's your warning about not installing in efi mode? ;p

i was easily able to install win 10 in efi mode using the dvd on annvme drive . i even upgraded from1803 > 1809. but all the fear mongering has me worried about bricking the mobo, so I'm trying to install in legacy mode.
booting up using alt to get the legacy mode version, the legacy installer doesn't work with the nvme controller...

maybe the new firmware prevents certs from being written to the rom now? how can we confirm this? i will doa binwalk eventually, but I'm the mean time, how safe is it now to install in efi?
[doublepost=1543260467][/doublepost]

My Objective - to force a Win 10 Installer DVD to boot in UEFI Mode on a 2010 Mac Pro without a boot screen

Holding the Option key while restarting a Win 10 Installer DVD produces two Installer boot choices on the Boot Manager Screen - UEFI or Windows (legacy-BIOS). Win 10 will automatically be installed to boot in the same mode chosen to boot the Installer.

But when a Mac Pro video card can’t produce a boot screen you can't choose. If you simply allow the DVD to boot automatically (by holding the C key while restarting) it ALWAYS boots in the legacy-BIOS mode. You also can't choose from the Startup Disk preferences pane. It only shows the Installer DVD with a single Windows icon, and that boots into legacy-BIOS mode.

I tried all sorts of versions of the Bless command from the terminal, but everything I tried to bless the EFI folder or EFI files only resulted in booting legacy-BIOS.

So I tried to modify the Win10 iso to create an installer DVD without any BIOS booting in hope it would then boot UEFI. According to the following Microsoft page it looked like removing the bootmgr file might do it, but the DVD would not boot at all when I removed the bootmgr file. I get a text message on the black startup screen that a boot manager could not be found, and then booting into an OS continues automatically.

https://docs.microsoft.com/en-us/pr...s/it-pro/windows-8.1-and-8/dn293283(v=win.10)​

If this is a frequent problem, you can remove the boot files for UEFI mode or BIOS mode to prevent the PC from booting in the wrong mode. If the PC firmware is set up to boot in the wrong mode, the media will immediately fail to boot, allowing you to immediately retry booting the PC into the correct mode.​

• Boot in UEFI mode: To prevent Windows PE from booting in BIOS mode, remove the bootmgr file on the root of the media.
• Boot in BIOS mode: To prevent Windows PE from booting in UEFI mode, remove the efi folder on the root of the media.

Does anyone have a solution to modify a Win 10 Installer DVD to force it to boot UEFI?

it is not true that starting a dvd with 'c' pressed always starts in legacy mode. for me that didn't work at all andi was forced to use the boot picker to get legacy.

on top of that, how do you see the windows installer without an efi gpu? neither efi nor legacy installers showed up with my rx580? unless you're doing a preconfigured remote install, how do you install Windows without being able to see the installer?

 

[tsialex]

hey tsialex, where's your warning about not installing in efi mode? ;p

i was easily able to install win 10 in efi mode using the dvd on annvme drive . i even upgraded from1803 > 1809. but all the fear mongering has me worried about bricking the mobo, so I'm trying to install in legacy mode.
booting up using alt to get the legacy mode version, the legacy installer doesn't work with the nvme controller...

maybe the new firmware prevents certs from being written to the rom now? how can we confirm this? i will doa binwalk eventually, but I'm the mean time, how safe is it now to install in efi?
[doublepost=1543260467][/doublepost]
it is not true that starting a dvd with 'c' pressed always starts in legacy mode. for me that didn't work at all andi was forced to use the boot picker to get legacy.

on top of that, how do you see the windows installer without an efi gpu? neither efi nor legacy installers showed up with my rx580? unless you're doing a preconfigured remote install, how do you install Windows without being able to see the installer?

I can safely test this type of thing, but i doubt that anyone else want to desolder/reprogram/solder the SPI flash if the Windows installed into UEFI mode starts kernel panicking like with MP51.0087.B00.

 

[PianoPro]

it is not true that starting a dvd with 'c' pressed always starts in legacy mode. for me that didn't work at all andi was forced to use the boot picker to get legacy.

on top of that, how do you see the windows installer without an efi gpu? neither efi nor legacy installers showed up with my rx580? unless you're doing a preconfigured remote install, how do you install Windows without being able to see the installer?

I have installed Win 10 legacy-BIOS several times in the last couple of months from DVD's created from a downloaded Windows 10 iso (iso must be converted to cdr before burning DVD in order to boot). Those DVD's ALWAYS boot to legacy-BIOS when holding down C key. You do NOT need an EFI GPU to see the Win installer screens (you only need that to see a boot selector screen - which you don't use when holding down C key to boot the DVD). Works perfectly fine with an RX-560 for instance.

 

[bookemdano]

I have installed Win 10 legacy-BIOS several times in the last couple of months from DVD's created from a downloaded Windows 10 iso (iso must be converted to cdr before burning DVD in order to boot). Those DVD's ALWAYS boot to legacy-BIOS when holding down C key. You do NOT need an EFI GPU to see the Win installer screens (you only need that to see a boot selector screen - which you don't use when holding down C key to boot the DVD). Works perfectly fine with an RX-560 for instance.

My experience as well with a Sapphire Pulse RX 580 8GB

 

[1151105]

I have installed Win 10 legacy-BIOS several times in the last couple of months from DVD's created from a downloaded Windows 10 iso (iso must be converted to cdr before burning DVD in order to boot). Those DVD's ALWAYS boot to legacy-BIOS when holding down C key. You do NOT need an EFI GPU to see the Win installer screens (you only need that to see a boot selector screen - which you don't use when holding down C key to boot the DVD). Works perfectly fine with an RX-560 for instance.

this is great news, because I'm trying it right now and it's not working. did you remove the efi file from the .cdr before you burned it? it is possible that i burned the dvd from an iso, but i did create the cdr for this purpose.

could anything else be in the way? you guys installed to nvme drives? shouldn't leave any other osx disk in? need to do pram?

i have a fresh install of Mojave from HS, then i created a cdr, then burned it to disk. it worked great for efi...

I've managed to boot into legacy mode [but had to use picker], but getting an error will not let me install win10.

 

[PianoPro]

this is great news, because I'm trying it right now and it's not working. did you remove the efi file from the .cdr before you burned it? it is possible that i burned the dvd from an iso, but i did create the cdr for this purpose.

could anything else be in the way? you guys installed to nvme drives? shouldn't leave any other osx disk in? need to do pram?

i have a fresh install of Mojave from HS, then i created a cdr, then burned it to disk. it worked great for efi...

I've managed to boot into legacy mode [but had to use picker], but getting an error will not let me install win10.

I did nothing to the Win 10 iso (ver 1803 the last 2 times I did it, and 17 something previous to that) except use Disk Utility to convert the iso to a .CDR and then tell it to burn that to a DVD. After that it was just hold-C to boot the DVD. You do need to remove the other drives in the Mac Pro else the installer gets confused when it converts an HFS partition to NTFS and sets up the Win recovery partition etc. Maybe your problem is not removing your other drives and that is keeping the DVD from booting? I don't recall that situation.

 

[1151105]

i took the drives out and did a pram reset. it allows me to access the legacy install [i think, low res]. however I'm getting this now:

so it doesn't like the nvme it seems. i had to whipe it using the terminal. i wasnt able to do it in disk utility. but then formatted as per h98*s post...

 

[PianoPro]

I did nothing to the Win 10 iso (ver 1803 the last 2 times I did it, and 17 something previous to that) except use Disk Utility to convert the iso to a .CDR and then tell it to burn that to a DVD. After that it was just hold-C to boot the DVD. You do need to remove the other drives in the Mac Pro else the installer gets confused when it converts an HFS partition to NTFS and sets up the Win recovery partition etc. Maybe your problem is not removing your other drives and that is keeping the DVD from booting? I don't recall that situation.

OK I just tried booting my Win 10 v1803 DVD with my Mac Pro full of drives. Here's what happened:

1st try: Held C key and pressed power button. Soon got a black screen with the single line of white text that said to press any key to boot from CD-ROM (or something like that - it's the normal message). I didn't release the C key until the message went away (just a couple of quick seconds) and then I immediately got the Windows 4-rectangle logo and the Mac Pro proceeded to boot fairly quickly into my WIN10 system (not the DVD Win10 installer).

My guess is that if I didn't have a Win 10 drive it would have booted into Mac OS, and I recalled from the past that I should NOT hold the C key down until the white text line message went away. But instead you need to release the C key at that point and quickly press any other key (probably the C key again would work too) BEFORE the message goes away. And you have to be alert and quick because the message goes away very quickly when the C key is still being held down. So ....

2nd try: Shutdown the Mac Pro again (after first rebooting into Mojave from Win 10). Held C key and pressed power button. This time as soon as I saw the single line of white text (no time to read it) I immediately released the C key and rapidly jabbed the Space bar (any key should do but maybe or maybe not the C key) 3 or 4 times before the white text line went away. I immediately got the Windows logo again, but this time the Win 10 Install DVD booted (takes quite a while before the Win 10 logo went away and the DVD Installation screen appears, but you can hear the DVD drive reading the DVD during that time).

So that's "the trick" and now I remember I previously also had to release the C key and rapidly press a key (several times to be sure) before the white text line goes away to boot the DVD. You do not have to remove other drives to make the DVD boot work, but you will have to remove other drives to install Win 10 during the normal installation process so that occurs naturally.

 

[1151105]

OK I just tried booting my Win 10 v1803 DVD with my Mac Pro full of drives. Here's what happened:

1st try: Held C key and pressed power button. Soon got a black screen with the single line of white text that said to press any key to boot from CD-ROM (or something like that - it's the normal message). I didn't release the C key until the message went away (just a couple of quick seconds) and then I immediately got the Windows 4-rectangle logo and the Mac Pro proceeded to boot fairly quickly into my WIN10 system (not the DVD Win10 installer).

My guess is that if I didn't have a Win 10 drive it would have booted into Mac OS, and I recalled from the past that I should NOT hold the C key down until the white text line message went away. But instead you need to release the C key at that point and quickly press any other key (probably the C key again would work too) BEFORE the message goes away. And you have to be alert and quick because the message goes away very quickly when the C key is still being held down. So ....

2nd try: Shutdown the Mac Pro again (after first rebooting into Mojave from Win 10). Held C key and pressed power button. This time as soon as I saw the single line of white text (no time to read it) I immediately released the C key and rapidly jabbed the Space bar (any key should do but maybe or maybe not the C key) 3 or 4 times before the white text line went away. I immediately got the Windows logo again, but this time the Win 10 Install DVD booted (takes quite a while before the Win 10 logo went away and the DVD Installation screen appears, but you can hear the DVD drive reading the DVD during that time).

So that's "the trick" and now I remember I previously also had to release the C key and rapidly press a key (several times to be sure) before the white text line goes away to boot the DVD. You do not have to remove other drives to make the DVD boot work, but you will have to remove other drives to install Win 10 during the normal installation process so that occurs naturally.

yes this sounds about whati did, excepti got no white lines of text. i just pressed c after the chime [loud come because of pram reset] held it until i could hear the cd 'sort of stop' being used. then i pressed space bar. booted into low res win installer.

what WAS different is that on previous [efi] installs, i was able to install to the drive no problem. but i have gathered that other people are able to boot to their nvme drives...

 

[PianoPro]

i took the drives out and did a pram reset. it allows me to access the legacy install [i think, low res]. however I'm getting this now:

so it doesn't like the nvme it seems. i had to whipe it using the terminal. i wasnt able to do it in disk utility. but then formatted as per h98*s post...

Read my post above about booting into the DVD (when to release C key and press another key, etc) and I don't think a PRAM reset will be necessary. I didn't need to do that.

So now you are booting the DVD with the C key and also seeing the Win Install process without an EFI GPU. Both things you said couldn't be done. Just kidding you a little
[doublepost=1543285287][/doublepost]

what WAS different is that on previous [efi] installs, i was able to install to the drive no problem. but i have gathered that other people are able to boot to their nvme drives...

So now I don't know what you are trying to do. Are you trying to install to NVME drive and getting that message? Or trying to install to SATA SSD or HD?

 

[1151105]

Read my post above about booting into the DVD (when to release C key and press another key, etc) and I don't think a PRAM reset will be necessary. I didn't need to do that.

So now you are booting the DVD with the C key and also seeing the Win Install process without an EFI GPU. Both things you said couldn't be done. Just kidding you a little
[doublepost=1543285287][/doublepost]
So now I don't know what you are trying to do. Are you trying to install to NVME drive and getting that message? Or trying to install to SATA SSD or HD?

indeed, the process is incredibly fussy. i wasnt doubting you guys, just getting different results. so needed to know what's different...

and now yes, i am stuck at that part with that error trying to install to a nvme.

currently in the process of trying again with a freshly burned dvd and fresh reformatted nvme... the windows are watching me but there is no circle

... it will come

... won't you circles?
[doublepost=1543287345][/doublepost]

indeed, the process is incredibly fussy. i want doubting you guys, just getting different results. shop needed to know what's different...

and now yes, i am stuck at that part with that error trying to install to a nvme.

currently in the process of trying again witha fresh burndvd and fresh reformatted nvme... the windows are watching me but there is no circle

... it will come

... won't you circles?

yeaaaaahhh, that's right circle. come to Daddy...

ok. I'm in... let's see if there is disappointment in the future
[doublepost=1543287790][/doublepost]

indeed, the process is incredibly fussy. i want doubting you guys, just getting different results. shop needed to know what's different...

and now yes, i am stuck at that part with that error trying to install to a nvme.

currently in the process of trying again witha fresh burndvd and fresh reformatted nvme... the windows are watching me but there is no circle

... it will come

... won't you circles?
[doublepost=1543287345][/doublepost]
yeaaaaahhh, that's right circle. come to Daddy...

ok. I'm in... let's see if there is disappointment in the future

yep... just as i suspected, disappointment

BUT
i did get a new additional error:

so, i must not be formatting the nvme disk correctly?

 

[bookemdano]

indeed, the process is incredibly fussy. i wasnt doubting you guys, just getting different results. so needed to know what's different...

and now yes, i am stuck at that part with that error trying to install to a nvme.

currently in the process of trying again with a freshly burned dvd and fresh reformatted nvme... the windows are watching me but there is no circle

... it will come

... won't you circles?
[doublepost=1543287345][/doublepost]
yeaaaaahhh, that's right circle. come to Daddy...

ok. I'm in... let's see if there is disappointment in the future
[doublepost=1543287790][/doublepost]
yep... just as i suspected, disappointment

BUT
i did get a new additional error:

so, i must not be formatting the nvme disk correctly?

in macOS, open disk utility. Click the View button on the toolbar and make sure "Show All Devices" is checked. Then select the top-level entry for your Win10 SSD (make absolutely certain you've selected the right disk). Click the Erase button on the toolbar. Give it a name, choose "MS-DOS (FAT)" as the format and "Master Boot Record" as the scheme, then click Erase and let it finish.

Remove all other hard drives and boot to your Win10 install CD holding c. When you get to the screen asking where you want to install Windows, select any partitions that appear in the list and delete them so no partitions appear in the list. Then click Next. Hopefully that will work for ya.

 

[1151105]

this is what i have been doing, but i've been using exFAT. could be that. i'll give it a try. although, would like support for larger files

 

[h9826790]

MVMe is considered external in MacOS. Windows can’t be installed directly on an external drive. Need work around.