Solved How to move boot sector such that I can remove an old drive?

A little while back I added a new PCIe 4.0 SSD drive and cloned my previous install from my old SSD.

I recently realized that my boot sector didn't change when the drive was cloned, so my PC will boot the correct drive, however the Active partition is on a different drive from my current and desired C: partition.

I'm using Win 11 Pro and am booting UEFI.
C: partition is on a GPT drive and has 'Boot, Page File, Crash Dump, and Basic Data Partition' flags
Active partition - the one I understand to have the boot sector on it - is a primary partition on an older MBR SSD

I am trying to move/recreate the boot sector on the new SSD so that I can remove the old drive.
I cannot mark the C: partition as active in Windows Partition manager (option is greyed out)
Have tried a couple of different utilities to create a boot sector, but haven't found anything which would seem to work.

It would seem that I should be able to use BCDboot from a command line to accomplish this, and googling has led me to believe I can type:

bcdboot c:\windows /s c:

to set the current C: partition of the new SSD to be the boot sector.
<EDIT> Online windows learning site says that the /s switch should not typically be used?!?
So, which switches do I need to just boot the new drive normally in the machine it is currently in and not be dependent on any other drives?

Need more info. Please open the Admin command prompt then type:
echo list disk | diskpart
Copy and paste the result.

I hope this video will guide you on your request also GPT partitions not mark as active partition.

In this video, i will show you how to create EFI partition from within Windows Recovery Environment.

In order to boot from the GPT disk, you will need to set your BIOS to boot in UEFI mode. If the computer is booting from an NTFS partition marked as active on an MBR disk, chances are extremely high that it is booting in legacy BIOS (CSM mode).

jw2k_fr said:

I recently realized that my boot sector didn't change when the drive was cloned, so my PC will boot the correct drive, however the Active partition is on a different drive from my current and desired C: partition.

Click to expand...

Hello @jw2k_fr and welcom to ElevenForum.

Anytime you have an issue like this, you should post a screenshot of Disk Management, with everything expanded horizontally, so we can read it.

A good Disk management screenshot should show ALL drives and partitions on your system (not just the one you think has the problem). All the writing in the upper and lower sections should be visible.

A good Disk Management screenshot, looks like this...





To post a screenshot on this forum...

1. Take the screenshot, edit it as desired, save to your desktop as .png or .jpg (max. size = 2MB)
2. Left click in your post, where you want to place the screenshot.
3. Click the Attach Files button at lower left, browse to your pic and click Insert.
4. After clicking Insert, I usually choose the Thumbnail option.

NavyLCDR said:

In order to boot from the GPT disk, you will need to set your BIOS to boot in UEFI mode. If the computer is booting from an NTFS partition marked as active on an MBR disk, chances are extremely high that it is booting in legacy BIOS (CSM mode).

Click to expand...

Hi there, thanks for the reply - I'm going by what's shown in MSINFO32 which says I'm booting UEFI.
Something happened about twelve months ago and I had to create a boot menu to allow me to choose which partition to boot, which probably added to this mess and potentially explains why I'm booting from an MBR partition into a GPT basic partition:

Ghot said:

Hello @jw2k_fr and welcom to ElevenForum.

Anytime you have an issue like this, you should post a screenshot of Disk Management, with everything expanded horizontally, so we can read it.

Click to expand...

As you can see, Disk2 is my newest SSD and I did set aside UNALLOCATED space on Disk2 for the EFI partition, but either it didn't get created or something happened during my attempts to get it to reliably boot Disk2

FreeBooter said:

I hope this video will guide you on your request also GPT partitions not mark as active partition.
In this video, i will show you how to create EFI partition from within Windows Recovery Environment.

Click to expand...

Thank you for the clarification and video, I'll see about converting that 200MB of free space on Disk2 into an EFI partition.

In this video, i will show you how to convert MBR disk to GPT disk without losing a data in Windows 10 and Windows 11. If your PC supports UEFI, then you could use the MBR2GPT tool to switch from an MBR to GPT disk without data loss.

@jw2k_fr


Open command prompt as admin, and type these two commands. Then post a screenshot of the result...
Just type: cmd in the Taskbar search box, and choose: Run as Administrator on the right side.






Assuming Disk 2 is really GPT, and the BIOS is set to UEFI...
then all you need to do is create the EFI System partition on Disk 2, and then delete the old one from Disk 3.

Ghot said:

Assuming Disk 2 is really GPT, and the BIOS is set to UEFI...
then all you need to do is create the EFI System partition on Disk 2, and then delete the old one from Disk 3.

Click to expand...

That it is cap'n...

Disk 1 is MBR to boot from Disk 1 you will need to set BIOS to legacy mode or CSM mode.

@jw2k_fr

You want to boot from Disk 2, correct?

The solution is easy. In a command prompt with admin privileges:

FreeBooter said:

Disk 1 is MBR to boot from Disk 1 you will need to set BIOS to legacy mode or CSM mode.

Click to expand...

Not looking to boot MBR. I think the ACTIVE tag on the old MBR SSD was actually a red herring. I think it will show an MBR Boot Sector partition as Active even if it's not booting from it. I believe the UEFI was looking at the EFI partition on Disk 3 and then booting my current C: partition on Disk 2 hence how I was in Windows in UEFI mode.

That old MBR drive has now been removed and the machine boots without it, see below.

Ghot said:

@jw2k_fr

You want to boot from Disk 2, correct?

Click to expand...

Correct

NavyLCDR said:

The solution is easy. In a command prompt with admin privileges:

Code:

diskpart
select disk 2
create part EFI
format fs=fat32 quick
assign letter=s
exit
bcdboot C:\Windows /s S: /f UEFI
diskpart
select volume s
remove
exit
exit

Click to expand...

I did something approximating this and I now have a WINDOWS BOOT MANAGER entry in the UEFI for disk2 which I was missing previously (w00t!). As you mentioned, I did not need to boot into the recovery environment. My only concern is that I didn't assign a drive letter to the EFI partition and I directed BCDboot to use the C: partition, however, I am guessing that windows is smart enough to infer that I meant the local EFI partition on the same drive when I specified that partition. Either way, it seems to boot correctly and my UEFI boot order specifies what was Disk 2 (now Disk 0 after removing the two old 2.5" SSDs)






Thank you to everyone who contributed and helped me work out what I was missing. Having previously been MCSE certified way back in '97 I've gotten lazy in the past decade and don't dig into this kind of thing more than once every few years - I'm starting to forget too much of it! Plus, you know when you're getting to be a dinosaur when it feels wrong to call the UEFI anything other than a BIOS... cos that's what it is... just a fancy graphical one

jw2k_fr said:

Thank you to everyone who contributed and helped me work out what I was missing.

Click to expand...

Well, I am glad you found a solution somewhere! It wasn't the solution I posted....

I think, there is a need for a better clear procedure to migrate a windows 11 system from one disk to another and migrate the Windows 11 Boot Manager from the old GPT disk to the new cloned disk or SSD. The UEFI Bios needs to be updated by bcdboot to point to the EFI partition and Windows Boot Manager of the new cloned disk.
All the procedures I find on the web, are obsolete and not specific to newer UEFI Windows 11 systems.