[SOLVED] Bootmgr is missing even after clean reinstall of windows 10

[DragonGunner]

Hi and happy holidays! I recently upgraded large parts of my computer for Black Friday. With these changes came the addition of two new ssds, one of which replaced my boot drive. I cloned the old c: (ssd) and everything worked fine. For a day. Then this morning I turned on my computer and it said boot manager is missing.

I've spoken at length with a Microsoft agent and they initially directed me to use bootrec command lines to repair MBR and fix boot - the latter of which did not work (denied access). Then tried in the winpe environment for installation of Windows to repair startup, which also didn't work. Looked at the drive through my EaseUS boot able thumb drive, and the format is now Raw.

Had lots of difficulty installing Windows 10 on the C: ssd, or for that matter anywhere else. I was eventually told to format my original C drive and reinstall Windows onto it, which I did. Imagine my shock when I turn on my computer again (with only that drive connected) and boot manager is still missing. I can still boot from the older, smaller ssd that I had used for the windows install. All drives are recognized by bios.

What went wrong?

My old parts are in my signature below. New ones as follows: 2x Crucial 2TB SSD, Gigabyte Aorus Wifi Pro, i7-9700k, 1x16GB T-Force Vulcan C ddr4 3200. Running windows 10 home, but upgraded a few weeks ago, before the hardware upgrade. It may also be worth noting that the drives replaced by the new ssds were dynamic drives and had to be cloned rather than copied.

As always, all input is enormously appreciated.

 

[rgd1101]

update the bios?

 

[USAFRet]

When you installed the OS on the SSD, did you have any other drive connected?

 

[DragonGunner]

When you installed the OS on the SSD, did you have any other drive connected?

Nope.

update the bios?

Just did that, and now bios is saying there are no bootable devices, even with the original windows installation plugged in.

 

[SkyNetRising]

Try different boot sequence settings until you can boot into windows.

Then show screenshot from Disk Management.

What are model names of the drives? Any of them M.2 ?

Side note - single ram module limits memory performance to single channel mode (memory bandwidth is essentially cut in half).

 

[DragonGunner]

Impropper cloning most likely.
Try different boot sequence settings until you can boot into windows.

Then show screenshot from Disk Management.

What are model names of the drives? Any of them M.2 ?

No, no M.2. I played with bios and it's recognizing drives and letting me boot with the old ssd again, but not the new one.

Idk about the clone - I did it with a easeus winpe instance, and it worked fine initially. Now [the new ssd is] not working even after a format and reinstallation of windows.

 

[SkyNetRising]

Would like to see screenshot from Disk Management.
(upload to imgur.com and post link)

 

[DragonGunner]

The C: drive is what I'm currently booting from - the old SSD. G: is the new SSD with its clean installation of Windows 10. Both G: and E: are the new SSDs: Crucial MX500 2.5" 2TB SATA III 3D NAND Internal Solid State Drive (SSD) CT2000MX500SSD1. E: is working fine, games are loading no problem.

 

[SkyNetRising]

Ok. This is, how you fix it. Execute from elevated command prompt. Regular command prompt will give error on last step.

How to open a Windows 10 Elevated Command Prompt

This tutorial will explain how to open an Elevated Command Prompt in Windows 10. You can use this Command Prompt to type commands that will be executed with Administrative privileges.

www.bleepingcomputer.com

If you get any errors, then stop immediately.

diskpart​

list disk​

select disk 2​

(select 1863GB disk)​

list partition​

select partition 1​

(select 1863GB partition)​

shrink desired=500​

create partition primary size=500​

format fs=ntfs quick​

assign letter=H​

active​

exit​

bcdboot G:\windows /s H:​

After that boot into BIOS and change boot priority to boot from 2TB drive.

 

[DragonGunner]

Ok. This is, how you fix it. Execute from elevated command prompt. Regular command prompt will give error on last step.

How to open a Windows 10 Elevated Command Prompt

This tutorial will explain how to open an Elevated Command Prompt in Windows 10. You can use this Command Prompt to type commands that will be executed with Administrative privileges.

www.bleepingcomputer.com

If you get any errors, then stop immediately.

diskpart​

list disk​

select disk 2​

(select 1863GB disk)​

list partition​

select partition 1​

(select 1863GB partition)​

shrink desired=500​

create partition primary size=500​

format fs=ntfs quick​

assign letter=H​

active​

exit​

bcdboot G:\windows /s H:​

After that boot into BIOS and change boot priority to boot from 2TB drive.

Everything went fine until "active" where it spouted "the selected disk is not a fixed MBR disk. The active command can only be used on fixed MBR disks."

 

[SkyNetRising]

Hmm. You have partitioned the new drive in GPT. Old drive was MBR.

Ok, then. Not a big problem. Slight alterations to script are necessary

Execute from elevated command prompt.
Again - if you get any errors, then stop immediately.

diskpart​

list disk​

select disk 2​

(select 1863GB disk)​

list partition​

select partition 1​

(select 1863GB partition, partition number can be 1 or 2)​

shrink desired=500​

create partition efi size=500​

format fs=fat32 quick​

assign letter=H​

exit​

bcdboot G:\windows /s H:​

After that boot into BIOS, set boot mode to UEFI and change boot priority to boot from Windows Boot Manager (2TB drive).

 

[SkyNetRising]

Show screenshot.

 

[DragonGunner]

Sorry, misread a little bit there. The new partition is I: now, and at bcdboot it gives "Failure when attempting to copy boot files".
Also, G: is now RAW again.

 

[DragonGunner]

 

[SkyNetRising]

Run chkdsk on G: drive

chkdsk /f G:​

If that doesn't fix RAW file system, then you'll have to reinstall or perform cloning.
Before install or cloning clean disk 2 with diskpart.

diskpart​

list disk​

select disk 2​

clean​

Disconnect all other drives if you decide to reinstall. Leave only one drive connected.

 

[DragonGunner]

Okay, the disk check didn't run because it's not available for RAW. Will do that bit with diskpart, unplug everything but C: and G: (new C and clone again.

 

[SkyNetRising]

For reinstall have only one drive connected.

 

[USAFRet]

If you're doing a clean install:

How To - Windows 10 clean install tutorial

If you are looking for the Windows 11 Clean install tutorial, you can find that here: Windows 11 Clean install tutorial (Click here) Otherwise, welcome to the Windows 10 Clean install tutorial This tutorial is intended to help you, step by step, to perform a clean install of Windows...

forums.tomshardware.com

 

[Ravi Sankar]

Can you disconnect all the drives other than the one you are installing OS and try fresh installation once

 

[DragonGunner]

Well I disconnected everything, cloned from the old SSD, reconnected, set the boot order, and everything's fine again. Thank you all for all your help and I hope this doesn't happen again!
Have a happy holidays <3

PS If anyone has any ideas about why the clone worked but reinstall didn't, or what I might have done to have cause this in the first place, PLEASE let me know your thoughts.

 

[SkyNetRising]

I'd suspect BIOS battery on your board has failed.

 

[DragonGunner]

I'd suspect BIOS battery on your board has failed.

Swapping that was one of the first things I tried. Is it possible that it happened due to a BSOD or rapid shutdown? That happened a few times.