SSD w/Win10 from old PC detected, not bootable? MBR/BIOS vs GPT/UEFI issue perhaps?

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RanceJustice

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Hello all. I'm now running on my new X99 platform rig (Rampage V Edition 10 Mobo), on which I had installed Win10 Pro x64 (unactivated as of yet) on a Samsung 960 EVO NVMe drive for overclocking and stability testing. However, I also pulled a handful of drives from my old X58 platform PC including the a Samsung 840 Pro w/Win 10 Pro x64 (activated) , a WD Black HDD without any OS acting as an overflow data drive in my old PC, and an old WD VelociRaptor with Win7 Ultimate x64.

All of these drives are detected by the W10Pro install on the 960 EVO, automatically visible and able to be browsed on the file manager. However, what I really wanted to do was to boot the Win10Pro on the 840 Pro. I had been told on some enthusiast forums and chats that W10Pro is pretty flexible and wouldn't have too much of an issue with drivers and whatnot, swapping the drive from one PC to another (a departure from earlier OSes as I recall), with the OS pulling down what it needs for core functionality in most cases. However, the problem I am having is that I can't seem to make the 840 Pro bootable at all.

When I go into my RVE10's UEFI and look at the boot options, all the drives are detected. Right now the 960 is of course the first boot drive, but there is a helpful Boot Override option where you can click on a particular drive and boot directly from that one it seems. When I try this with the 840 Pro however, sadly it does not actually boot. I get about a second of the "flashing cursor on black screen" before rebooting into the BIOS/UEFI. Its also noteworthy that unlike on my old PC, Win10 (on 960 EVO) does not automatically detect there are multiple windows installs on different drives and give me the chance to pick the one I wish to boot through its boot manager; my old PC used to give me the chance to boot Win10 (on 840) and Win 7 (on VelociRaptor) with every reboot.

Can anyone think of a reason for this or a way to boot the OSes on other drives? I've come up with a couple of theories of things that could affect it.

First, I wonder how much of this is because the new/native Win10Pro install on the 960 EVO is obviously using UEFI (possibly GPT?) parameters, whereas the old W10Pro on the 840 Pro was from the X58 days where it was using the old style BIOS (MBR?). I seem to remember that W10 will automatically decide on certain settings for one or the other given the circumstances of the install, and this can affect different things (Notably, certain activation technologies for Win7 would work on BIOS mode, but not UEFI mode ). Could this have anything to do with it and if so is there a certain setting I need to toggle or other fix that might help?

Next, I wonder if it has to do with Secure Boot or similar settings? I've left the Secure Boot on the default for the RVE10 and though I am pretty sure any W10 install should be compliant, maybe because it was installed on an old chipset without any SecureBoot support could introduce an issue.

Anything else worth looking into or solutions to try?
 
The ability to swap the OS drive between wildly varying platforms is by no means guaranteed, even under Windows 10.
 
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That's true, but we haven't even gotten to Windows 10 as of yet. If it doesn't work, it doesn't work - so long as I preserve the data all is well. However, the more reading I do it seems that a most likely issue keeping the older drive from booting has to do with it being on MBR.

I've been picking through ways to convert a drive with a MBR Win10 install to GPT. Unfortunately the simplest ways to do so seem to require deleting everything on the disk, so yeah...that's undesirable. It seems there are quite a few 3rd party partition tools (mostly Windows programs. I'll have to look into Linux liveCDs and whanot like PartedMagic, if they can handle this relatively delicate change) out there that claim to be able to move from MBR to GPT without data loss, so maybe that's a way to go. However, I recently came across - https://docs.microsoft.com/en-us/windows/deployment/mbr-to-gpt - Which seems to be a relatively new utility, direct from Microsoft themselves and only included in the 2017 W10 Creators update or newer, that seems to do exactly what is needed! Anyone have experience with this? There seems to be reasonable documentation there thankfully, which is good considering this isn't something that can be implemented in a few clicks, instead relying on proper CLI use.

I'm fairly sure now that without converting to GPT, its unlikely I'll be able to boot the old, MBR W10 install so no matter what comes later, this seems like the next step. The only workaround I can think of is if I can configure my motherboard to accept a legacy boot / BIOS situation, but I don't know what ramifications that might have (besides not being able to boot the UEFI drives until I switch it back), especially as I did a lot of my configuration/overclocking/settings stuff under the enhanced UEFI interface. In any event, it seems the simple thing - IF it works and safely - would be to convert the MBR to GPT. If anyone has done so in the past and has any tips, they'd be appreciated. Thanks!
 
When you install as a GPT disk (uefi mode) you boot to the Windows Boot Manager, not the actual drive.

And yeah, if you swap the drive into a different PC with secure boot on it should not work.

Try booting to a Windows 10 install disk that matches the version you have installed and run a start-up repair.
 
bigdogchris said:
When you install as a GPT disk (uefi mode) you boot to the Windows Boot Manager, not the actual drive.

And yeah, if you swap the drive into a different PC with secure boot on it should not work.

Try booting to a Windows 10 install disk that matches the version you have installed and run a start-up repair.
Click to expand...

This is a very valid point, secure boot's gonna halt all the fun.
 
bigdogchris said:
When you install as a GPT disk (uefi mode) you boot to the Windows Boot Manager, not the actual drive.

And yeah, if you swap the drive into a different PC with secure boot on it should not work.

Try booting to a Windows 10 install disk that matches the version you have installed and run a start-up repair.
Click to expand...

I'm not sure that SecureBoot is causing an issue -yet. For that matter, it seems that the default RVE10 UEFI/BIOS option appears to allow some flexibility for CSM / Legacy boot, if needed. There are multiple options here as well as simply turning off SecureBoot - something I may do anyway if need be, as I've not yet looked into what Linux distros and bootloaders are SecureBoot compliant and which aren't (I seem to remember that certain distros and tools like GRUB basically bought a valid SecureBoot key registration, so they can be booted without deactivating SecureBoot). In any event, I'm pretty sure the GPT issue is the primary one so far. When I start getting SecureBoot errors then I'll have to address that I suppose.

I've tried to use the GPT2MBR tool and unfortunately it fails the validation step. Picking through logs, this seems to be because there is no (MBR-style) boot flagged partition on the old 840 Pro " ValidateLayout: Wrong boot partition count, expected 1 but found 0 " is the error message. Opening Disk Management, the 840 Pro has 2 partitions on it - 1 primary partition that pretty much takes up the majority of the drive, and another primary partition that is 450mb listed as a Recovery Partition. So I guess the thing I need to do is create a MBR-compliant boot partition on the drive, right? Does anyone have a tutorial on exactly how to go about doing that? Assuming that I'm reading the right things that are in reference to a MBR style partition as opposed to a GPT one, doesn't a MBR style install of Win10 usually create a 100mb "system reserved" partition on the drive , which is then filled with the proper Boot files and flagged as Bootable? I can certainly shrink my main data partition by a couple hundred MB just to be safe, but I need to ensure that I create it in the right way I'm sure (does it matter where on the drive the partition itself is found? Where shall Io get the files that need to be on the partition? Etc)?

I tried using a Win10 install disk and running StartUp repair. It seems to fail. In fact, it seems to basically claim not to be able to do anything, and if I'm correct it was trying to interact with the Win7 drive, not the Win10 drive? Maybe I'll try it again if I disconnect the Win7 drive. However, I seem to remember that the StartUp Repair tool can fix some things, but according to one thing I read if I'm correct that missing a boot partition at all is an issue, it won't create one/fix that?

If there's a relatively viable way to add a new MBR-compliant boot partition, then I'd figure that is the thing to try, so that I can attempt running MBR2GPT again. However if it doesn't work or other issues continue to rear their heads, it may not be worth all the trouble; I'll configure my new Win10 install on the NVMe drive instead for actual use, and then just go onto the other drives as data drives instead and back up what I need.

Thanks.
 
Xaeos said:
Hello all. I'm now running on my new X99 platform rig (Rampage V Edition 10 Mobo), on which I had installed Win10 Pro x64 (unactivated as of yet) on a Samsung 960 EVO NVMe drive for overclocking and stability testing. However, I also pulled a handful of drives from my old X58 platform PC including the a Samsung 840 Pro w/Win 10 Pro x64 (activated) , a WD Black HDD without any OS acting as an overflow data drive in my old PC, and an old WD VelociRaptor with Win7 Ultimate x64.

All of these drives are detected by the W10Pro install on the 960 EVO, automatically visible and able to be browsed on the file manager. However, what I really wanted to do was to boot the Win10Pro on the 840 Pro. I had been told on some enthusiast forums and chats that W10Pro is pretty flexible and wouldn't have too much of an issue with drivers and whatnot, swapping the drive from one PC to another (a departure from earlier OSes as I recall), with the OS pulling down what it needs for core functionality in most cases. However, the problem I am having is that I can't seem to make the 840 Pro bootable at all.

When I go into my RVE10's UEFI and look at the boot options, all the drives are detected. Right now the 960 is of course the first boot drive, but there is a helpful Boot Override option where you can click on a particular drive and boot directly from that one it seems. When I try this with the 840 Pro however, sadly it does not actually boot. I get about a second of the "flashing cursor on black screen" before rebooting into the BIOS/UEFI. Its also noteworthy that unlike on my old PC, Win10 (on 960 EVO) does not automatically detect there are multiple windows installs on different drives and give me the chance to pick the one I wish to boot through its boot manager; my old PC used to give me the chance to boot Win10 (on 840) and Win 7 (on VelociRaptor) with every reboot.

Can anyone think of a reason for this or a way to boot the OSes on other drives? I've come up with a couple of theories of things that could affect it.

First, I wonder how much of this is because the new/native Win10Pro install on the 960 EVO is obviously using UEFI (possibly GPT?) parameters, whereas the old W10Pro on the 840 Pro was from the X58 days where it was using the old style BIOS (MBR?). I seem to remember that W10 will automatically decide on certain settings for one or the other given the circumstances of the install, and this can affect different things (Notably, certain activation technologies for Win7 would work on BIOS mode, but not UEFI mode ). Could this have anything to do with it and if so is there a certain setting I need to toggle or other fix that might help?

Next, I wonder if it has to do with Secure Boot or similar settings? I've left the Secure Boot on the default for the RVE10 and though I am pretty sure any W10 install should be compliant, maybe because it was installed on an old chipset without any SecureBoot support could introduce an issue.

Anything else worth looking into or solutions to try?
Click to expand...

Your 840 Pro is an MBR legacy boot drive. You cannot boot that drive unless you set your bios to legacy, Non UEFI GPT boot mode. The thing is, NVMe does not support anything but GPT, at least that I am aware of, so you would not be able to choose between the two at the same time.
 
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