[SOLVED] Newly installed Windows only boots if old SSD is plugged in

Jan 3, 2021
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I was using Windows 10 on a SATA SSD. I decided to install Windows 11 on an NVMe using a Windows 11 ISO file that I flashed onto an external drive.

However, I noticed that the Windows 11 installation on my NVMe did not boot up by itself—it would go straight into the BIOS. Now when I want to boot into my NVMe, I need to connect my old SATA SSD to my computer, turn it on, and then select Windows 11 as my boot option (from choices of Win 11 and Win 10).

Why is the UEFI not recognizing my NVMe as a bootable disk even though I can run Windows just fine on it? How do I make it so that it can boot into Windows on its own without my needing to keep the old SSD plugged in?
 
Disk 0 is the old SSD with Windows 10 installed. Disk 1 is the one I am running, the NVMe drive with Windows 11 installed. Being able to create a boot partition manually would be the ideal option for me!
Execute following from elevated command prompt.
diskpart
list disk
select disk 1
list partition
select partition 1
(select 200MB EFI system partition)​
assign letter=H
exit
bcdboot C:\windows /s H: /f UEFI /v
Show screenshot with command output.

If there are no errors, you should be able to disconnect old SSD and boot from new nvme drive.
Make Windows Boot Manager as first option in boot priority in BIOS.

 
Reactions: donutcoffee
Jan 3, 2021
44
2
35
0
I'm guessing you did this install with the old SSD still connected?
This is what happens.
The boot partition exists on the old drive.

Redo the install, with ONLY the new drive connected.
Yes, I think that's what I did. And oh no! Do I need to reinstall windows from scratch? I spent a lot of time setting it up, transferring my files over, and installing my favorite applications :(
 
Jan 3, 2021
44
2
35
0
I'm guessing you did this install with the old SSD still connected?
This is what happens.
The boot partition exists on the old drive.

Redo the install, with ONLY the new drive connected.
I tried to reinstall Windows with only the new drive installed, but it didn't detect that version of windows so I could not do an "upgrade" install. Does that mean I have to format it and then do an install that way?
 

USAFRet

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I tried to reinstall Windows with only the new drive installed, but it didn't detect that version of windows so I could not do an "upgrade" install. Does that mean I have to format it and then do an install that way?
Did you boot directly from your USB?

 
Jan 3, 2021
44
2
35
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Did you boot directly from your USB?

So that means I really do reinstall it from scratch? No way to reinstall just the EFI partition?
 
Jan 3, 2021
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The Win 11 is the one that is screwed up?

Yes, reinstall it.
Darn. Is there any way to make it easier, like making a backup first and then restoring from it after reinstallation? Sorry, I'm a noob at Windows and don't really know about any similar procedures. I don't want to reinstall all my applications and re-configure them and customize all my settings all over again 😢
 
Jan 3, 2021
44
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35
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Jan 3, 2021
44
2
35
0
Can you boot to your original C drive?
If so, perhaps you can clone your C drive to the m.2 ssd and proceed from there.
That's a good suggestion although unfortunately I did want a clean start so didn't want to copy stuff off the old drive to the new drive. However I suppose I could clone things from my "old" NVMe to a new NVMe
 
Disk 0 is the old SSD with Windows 10 installed. Disk 1 is the one I am running, the NVMe drive with Windows 11 installed. Being able to create a boot partition manually would be the ideal option for me!
Execute following from elevated command prompt.
diskpart
list disk
select disk 1
list partition
select partition 1
(select 200MB EFI system partition)​
assign letter=H
exit
bcdboot C:\windows /s H: /f UEFI /v
Show screenshot with command output.

If there are no errors, you should be able to disconnect old SSD and boot from new nvme drive.
Make Windows Boot Manager as first option in boot priority in BIOS.

 
Reactions: donutcoffee
Jan 3, 2021
44
2
35
0
Execute following from elevated command prompt.
diskpart
list disk
select disk 1
list partition
select partition 1
(select 200MB EFI system partition)​
assign letter=H
exit
bcdboot C:\windows /s H: /f UEFI /v
Show screenshot with command output.

If there are no errors, you should be able to disconnect old SSD and boot from new nvme drive.
Make Windows Boot Manager as first option in boot priority in BIOS.

Thanks for the suggestion! Here is what I got as my output: www.pastebin.com/fZTZ9irF

As you can see, I'm getting a lot of "Unable to open file" errors
 

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