[SOLVED] Changing Windows boot manager drive

Qwob

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Nov 24, 2016
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I've recently installed Windows 10 on my new m.2 but when I unplugged my old HDD to perform an easier format on a different HDD, I only reached BIOS as the m.2 does have the OS on it but not the EFI system file partition.

How can I put windows boot manager on my m.2? as I may need to trash/upgrade the HDD down the line because it is around 6-7 years old now
 
Recreate bootloader on M.2 drive.

First - make sure M.2 drive is partitioned in GPT partition style.
(in disk management right-click on "Disk 1", choose properties/volumes and find Partition Style)

Then execute from elevated command prompt. Regular command prompt will give error on last step.
https://www.bleepingcomputer.com/tutorials/how-to-open-a-windows-10-elevated-command-prompt/
(Stop immediately, if you get any errors!)

diskpart
list disk
select disk 1
list partition
select partition x
(select 465GB partition, x = 1 or 2)
shrink desired=500
create partition efi
format fs=fat32 quick
assign letter=H
exit
bcdboot C:\windows /s H:
Then shutdown your pc, disconnect hdd and try booting from M.2 drive.
 
Last edited:

Lutfij

Titan
Moderator
Mind sharing a screenshot of your partitions as shown on Disk Management in OS? It seems like you didn't install the OS the right way(or you cloned it). The only way you can have the Boot Manager on the SSD is if you had it during OS installation.

Backup your critical data, then reinstall the OS with the HDD unplugged from the system, format the SSD and install the OS. Prior to installing, create your bootable installer using Windows Media Creation Tools.
 

Qwob

Reputable
Nov 24, 2016
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Mind sharing a screenshot of your partitions as shown on Disk Management in OS? It seems like you didn't install the OS the right way(or you cloned it). The only way you can have the Boot Manager on the SSD is if you had it during OS installation.

Backup your critical data, then reinstall the OS with the HDD unplugged from the system, format the SSD and install the OS. Prior to installing, create your bootable installer using Windows Media Creation Tools.
https://prnt.sc/qy9r71

Yeah, I probably should have removed my HDD when reinstalling. Is the only way to format and reinstall again?
 
Recreate bootloader on M.2 drive.

First - make sure M.2 drive is partitioned in GPT partition style.
(in disk management right-click on "Disk 1", choose properties/volumes and find Partition Style)

Then execute from elevated command prompt. Regular command prompt will give error on last step.
https://www.bleepingcomputer.com/tutorials/how-to-open-a-windows-10-elevated-command-prompt/
(Stop immediately, if you get any errors!)

diskpart
list disk
select disk 1
list partition
select partition x
(select 465GB partition, x = 1 or 2)
shrink desired=500
create partition efi
format fs=fat32 quick
assign letter=H
exit
bcdboot C:\windows /s H:
Then shutdown your pc, disconnect hdd and try booting from M.2 drive.
 
Last edited:

Qwob

Reputable
Nov 24, 2016
16
0
4,510
0
Recreate bootloader on M.2 drive.

First - make sure M.2 drive is partitioned in GPT partition style.
(in disk management right-click on "Disk 1", choose properties/volumes and find Partition Style)

Then execute from elevated command prompt. Regular command prompt will give error on last step.
https://www.bleepingcomputer.com/tutorials/how-to-open-a-windows-10-elevated-command-prompt/

diskpart
list disk
select disk 1
list partition
select partition x
(select 465GB partition, x = 1 or 2)
shrink desired=500
create partition efi
format fs=fat32 quick
assign letter=H
exit
bcdboot C:\windows /s H:
Then shutdown your pc, disconnect hdd and try booting from M.2 drive.
Thanks, ill try this when i've backed up my files
 

leogobbo

Distinguished
Nov 1, 2012
5
0
18,510
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Recreate bootloader on M.2 drive.

First - make sure M.2 drive is partitioned in GPT partition style.
(in disk management right-click on "Disk 1", choose properties/volumes and find Partition Style)

Then execute from elevated command prompt. Regular command prompt will give error on last step.
https://www.bleepingcomputer.com/tutorials/how-to-open-a-windows-10-elevated-command-prompt/
(Stop immediately, if you get any errors!)

diskpart
list disk
select disk 1
list partition
select partition x
(select 465GB partition, x = 1 or 2)
shrink desired=500
create partition efi
format fs=fat32 quick
assign letter=H
exit
bcdboot C:\windows /s H:
Then shutdown your pc, disconnect hdd and try booting from M.2 drive.
I just want to thank you for the perfect reply, which solved my problem, and quickly add some notes in blue below explaining the steps that are being taken, in case someone like me, who did not understand exactly what was going on for every command and therefore was worried if this applied exactly to my situation, tries to do the same (and is worried about why am I shrinking something). I am an amateur so sorry for any imprecisions.

diskpart --> initiates the diskpart command
list disk --> lists all disks currently active
select disk 1 --> this is where you choose to which disk you want to change your bootloader
list partition --> lists all partitions on currently selected disk
select partition x (select 465GB partition, x = 1 or 2) --> select the partition which we will shrink to fit the new system partition where the bootloader will go. There is probably already a small "reserved" partition in your drive, which has nothing to do with booting windows.
shrink desired=500 --> we are shrinking the partition in 500mb to allow for open space in the drive where the bootloader will go in a new, separate partition. 500mb is the bootloader size partition for Windows 10, other versions have different sizes.
create partition efi --> creates the new system partition which will house the bootloader
format fs=fat32 quick --> formats the system partition. I'm not sure why we are using fat32, but I trust @SkyNetRising knows this is the best or required format. Otherwise, quick just means we are not fully erasing everything in there, just quickly doing the formatting.
assign letter=H --> assigning a letter to the drive. Any letter will do actually, I used Z because H was already used in my PC. It would seem the choice here is not relevant as long as the letter is free.
exit --> bye bye diskpart
bcdboot C:\windows /s H: --> bcdboot configures the boot files in the new partition. /s is the command to indicate you want the boot files in a specific drive - in this case, H: If you chose a different drive letter above (as I chose Z) you should choose the same letter here, indicating it is where the new boot files should go.
 
You did a good research.
Couple notes ..
format fs=fat32 quick --> formats the system partition. I'm not sure why we are using fat32. Otherwise, quick just means we are not fully erasing everything in there, just quickly doing the formatting.
UEFI bootloader partition requires fat32 formatting. For legacy bootloader partition use ntfs instead.
Formatting erases everything on partition being formatted. Full vs quick format means after formatting also scan for bad blocks is being performed (can take a long time on large partitions). Quick format omits this extra scan.
 
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