New install on NME SSD But Old EFI on another drive


  1. Poorman65
    Posts : 10
    Windows 10 Pro
       New #1

    New install on NME SSD But Old EFI on another drive


    I installed Windows 10 Pro on my new SSD drive and I don't see a partition created for the EFI. I put another drive in which happens to have an EFI on it. I tried to delete the partition, but don't seem to be able to. It claims to be the Active System Partition. In Disk Management it shows it as (System, Primary Parition).

    So, my boot drive is loading as Disk 1 and has my C: partition. That is where the installation of Windows is.

    It doesn't seem to have any trouble booting up properly, but there are some strange things happening that I think may be related to this. When I run msconfig, the "Boot" tab doesn't have any available OS. This makes it so I can't select Safe Boot.

    I can't seem to get to Safe Mode through the Recovery options or by pressing F8 either.

    I tried running EasyBCD to see what it was looking at and it says "The boot configuration data store could not be opened. The requested system device cannot be found".

    I've attached my Disk Management Screen.

    Really confused about what I am dealing with here. I appreciate any help!
    Attached Thumbnails Attached Thumbnails New install on NME SSD But Old EFI on another drive-diskmanagement.png  
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  3. bro67
    Posts : 9,789
    Mac OS Catalina
       New #2

    - Boot the computer using the Windows 7/8/8.1/10 installation media.
    - On the first screen, press SHIFT+F10 to bring up the command prompt.
    - Run the following commands at the command prompt.

    diskpart
    list disk
    select disk # Note: Select the disk where you want to add the EFI System partition.
    list partition
    select partition # Note: Select the Windows OS partition (# number) or your data partition.
    shrink desired=100
    create partition efi size=100
    format quick fs=fat32
    assign letter=s
    list partition
    list volume Note: Note the volume letter where the Windows OS is installed.
    exit

    bcdboot X:\windows /s S:
    Note: Replace "X" with the volume letter of the Windows OS partition.

    BCDBoot copies the boot files from the Windows partition to the EFI System partition and creates the BCD store in the same partition.

    Remove the Windows installation media and restart the computer into your BIOS settings and set the SSD as the First Boot Device.
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  4. AddRAM
    Posts : 4,594
    Windows 10 Pro
       New #3

    You did not unplug Disk 0 before you installed Windows on Disk 1 did you ?

    That partition has your System files on it, that`s why you can`t delete or format it, Windows won`t let you, this is perfectly normal.

    Disk 1 has no System files on it, if you unplug Disk 0, Windows will not boot.

    Always, Always, Always, install Windows with all other drives unplugged. (power cable) or possibly just disable the drive in the Bios, but I don`t do it that way.

    You should also consider swapping the Sata data cables from Disk 0 to Disk 1 and vice versa so C will be 1st on the boot list, but that is not a big deal, but it should be done
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  6. Poorman65
    Posts : 10
    Windows 10 Pro
    Thread Starter
       New #4

    When I initially installed this, the NME SSD was the only drive in the system. It is not a cable based drive, so there is no cable that can be swapped to put it first. Maybe there is a BIOS setting.

    The D drive used to be a bootable Windows drive years ago in another system. It no longer has Windows on it, but it still had the old EFI partition.

    Anyways, I got it working based on a clue from Bro67. For some reason, when I added the SATA drive. the BIOS placed it first in the Boot order. Once I found this, I put it at the bottom of the boot order. The system then booted up straight from my NME drive. It looks like, it was booting up using the old EFI partition, but not properly.

    Once I was able to start up without the Drive 0 EFI, I was able to go into Disk Management, delete the volume, and extend the partition for my D: drive. I also was able to boot into Safe Mode in the normal ways.

    Bro67, I had tried to mess with creating a partition for a clean EFI volume on my NME drive prior to my original post, but it complained that it was not GPT. I didn't want to mess with converting it, since I didn't understand that stuff very well. It also seemed odd that there wasn't already an EFI volume from the original install.

    Since I no longer have a visible EFI partition, how does this work now? Clearly there wasn't a partition created on the NME drive when I initially installed Windows 10. There must be some other technique at play here.

    Thanks you both for the help on this. I was stuck for most of the day.
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  7. bro67
    Posts : 9,789
    Mac OS Catalina
       New #5

    MBR does not need the EFI partition. Converting to GPT is your choice.

    https://docs.microsoft.com/en-us/win...ent/mbr-to-gpt
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  8. Poorman65
    Posts : 10
    Windows 10 Pro
    Thread Starter
       New #6

    I think I'm good with MBR. I just got messed up because the old EFI partition snuck into the mix. Thanks for the explanation and the help!
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  9. Abaximan
    Posts : 1
    Windows 11
       New #7

    bro67 said:
    - Boot the computer using the Windows 7/8/8.1/10 installation media.
    - On the first screen, press SHIFT+F10 to bring up the command prompt.
    - Run the following commands at the command prompt.

    diskpart
    list disk
    select disk # Note: Select the disk where you want to add the EFI System partition.
    list partition
    select partition # Note: Select the Windows OS partition (# number) or your data partition.
    shrink desired=100
    create partition efi size=100
    format quick fs=fat32
    assign letter=s
    list partition
    list volume Note: Note the volume letter where the Windows OS is installed.
    exit

    bcdboot X:\windows /s S:
    Note: Replace "X" with the volume letter of the Windows OS partition.

    BCDBoot copies the boot files from the Windows partition to the EFI System partition and creates the BCD store in the same partition.

    Remove the Windows installation media and restart the computer into your BIOS settings and set the SSD as the First Boot Device.
    Thank you so much. This saved me hours to intall everything again. Much apriciated!!!
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  10. Megahertz
    Posts : 6,303
    Windows 11 Pro - Windows 7 HP - Lubuntu
       New #8

    Just for the record
    - Disk 0 is Legacy-MBR (it has a active partition)
    - Disk 1 is Legacy-MBR (it has a active partition)

    - A boot able GPT drive must have a EFI Fat32 partition to hold the boot manager.
    - A Boot able MBR can boot as legacy to the active partition or as EFI if it has a EFI Fat32 partition to hold the boot manager. Drive 0 has a active partition so it should be a MBR. It may also boot as UEFI as it also has the EFI Fat32 partition.
    To find out, open Disk Manager View - Top - List Disk
    New install on NME SSD But Old EFI on another drive-dm3.jpg

    The instructions gave by bro67 on post #2 are correct but it should be applied to a GPT drive and not to a MBR drive. You can create the EFI partition and then, with the help o a good Disk Manager (like Minitool or Aomei) convert the drive from MBR to GPT without loosing data. In my opinion a conversion from Legacy-MBR to UEFI-GPT is much easier to achieve with MBR2GPT

    Windows can be installed in two ways: Legacy-MBR or UEFI-GPT
    To install as Legacy-MBR you must boot the installation drive as Legacy
    To install as UEFI-GPT you must boot the installation drive as UEFI.

    If you have a new MB (that has UEFI BIOS), you should install as UEFI-GPT
    Detach any other drives (SATA or Power cable) from the MB (or you may end with the OS in one drive and the boot manager in another).

    During POST, press F12(?) to launch the boot menu. You will see two options for the USB drive. USB UEFI (Name) and USB (Name). Select USB UEFI (Name).
    Go to install and delete ALL partitions on the SSD till you have one and only one unallocated space and then proceed.
    If you don't want to use MS account, don't enable updates or connect to the internet during installation.
    Last edited by Megahertz; 01 Mar 2022 at 15:28.
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  12. hani yassine
    Posts : 1
    Windows 10
       New #9

    bro67 said:
    - Boot the computer using the Windows 7/8/8.1/10 installation media.
    - On the first screen, press SHIFT+F10 to bring up the command prompt.
    - Run the following commands at the command prompt.

    diskpart
    list disk
    select disk # Note: Select the disk where you want to add the EFI System partition.
    list partition
    select partition # Note: Select the Windows OS partition (# number) or your data partition.
    shrink desired=100
    create partition efi size=100
    format quick fs=fat32
    assign letter=s
    list partition
    list volume Note: Note the volume letter where the Windows OS is installed.
    exit

    bcdboot X:\windows /s S:
    Note: Replace "X" with the volume letter of the Windows OS partition.

    BCDBoot copies the boot files from the Windows partition to the EFI System partition and creates the BCD store in the same partition.

    Remove the Windows installation media and restart the computer into your BIOS settings and set the SSD as the First Boot Device.
    I created this account just to say i freaking love you! you saved from reformatting my windows after i spent hours tweaking it after my format only to find out the efi partition in on the old ssd <3
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