Conversion of Legacy to UEFI Win 10

datcoor said:

Apologies for this lengthy post. Since my recent post regarding changing to a UEFI system, I elected to validate my system for conversion to UEFI using mbr2gpt.exe /validate. Since I was doing this through the running Win 10 system, I also had to use the / forallos option. As expected, because two SSDs had four partitions, the validation failed. A disc map is attached showing the current situation. Sorry, not uploaded since it is invalid doc file. Will sort this later if required.
Which is where things fell apart. On the next boot, the system booted from the SSD (Win OLD) which in fact contained an old version of Win 10. I was totally unaware of this since the system had been booting off another SSD (Win 10 NEW) for months. (The reason for this was that I decided some considerable time ago, to clone Win 10 onto the larger SSD Win 10 NEW, but left the Win 10 OLD SSD connected and altered the boot priority to boot off Win 10 NEW. This was not a dual boot situation and I left the Win 10 OLD in place as a fall back option)
Days after the validate, things became suspicious when Windows Update reported that my device was missing important security updates and so began downloading all the updates which the non operating Win 10 OLD had missed. I finally tumbled to what was going on when I saw that Win 10 OLD was now the C: drive. Now, OLD has downloaded all 21H2 updates and has commenced downloading 22H2. The reason for this is that support for 21H2 has ceased and Windows Update automatically downloads 22H2.
So it appears to me that the validate had recognised Win 10 OLD, it was on Disk 0, and proceeded to accept the MBR but rejected validation based on the four partitions. Not sure about this since the three recovery partitions are empty. Attached is the disc map.. At the same time, it seems to have disabled the MBR on Win 10 NEW. Consequently, I now cannot change the boot priority since the BIOS no longer recognises Win 10 NEW as it is now a non bootable drive. I had not expected the validate to alter MBR on Win 10 NEW.
I think I have some options.
1) Change nothing and let OLD update to 22H2. Then decide :
a) To use an image I made of Win 10 NEW prior to requesting the 22H2 download to restore NEW ie complete with its own MBR. I can then change the boot priority to boot off NEW.
Or
b) Image the newly updated OLD, (22H2) and clone that onto the larger SSD. I can then choose NEW in BIOS to boot from.
2) It may be possible to rewrite the MBR in Win 10 NEW so that it can be seen as a bootable drive in BIOS.

I do not understand why the validate operation removed the MBR from Win 10 NEW.
I do not understand why Avast security would not have had to download all the updates necessary to Win 10 OLD although it did flag that I was not protected. Checking on my Avast account showed that all was well as did Windows Security. Eventually after a couple of days the flag disappeared which suggests that Avast had brought itself up to date although it is set to update manually.
Hope I haven't bored you all with this but it has been a struggle to decipher what was happening. If I have it wrong, perhaps someone could advise. I don't normally like to quote my age but perhaps at 87, I am getting a bit beyond all this !

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This is the disc map which I had to convert sorry for delay

Is this still going on?

from the screenshot you can see that your bios is picking up disk 0 as first bootable device

therefore detach disk 0 and check it boots into the new os.

If so, reattach disk 0 and mark disk 0 part 1 inactive or swap the bios boot order.

D was not shown in BIOS as a bootable

I don't know what that means. Does your bios show drive letters ?

SIW2 said:

Is this still going on?

from the screenshot you can see that your bios is picking up disk 0 as first bootable device

therefore detach disk 0 and check it boots into the new os.

If so, reattach disk 0 and mark disk 0 part 1 inactive or swap the bios boot order.



I don't know what that means. Does your bios show drive letters ?

It will not pick up the Win 10 New system to boot since this is not shown in the BIOS screen as a bootable drive. You are right, BIOS does not show drive letters. It is a GUI and shows the bootable drive identified by make but the Win 10 NEW drive is not shown. Therefore it is not bootable.

Thanks to Megahertz for the very complete instructions. I use Macrium Reflect for imaging.
Thanks also to sapakakons and NavyLCDR for your comments.
I feel I have so many suggestions to work through and I am pretty well overwhelmed with the consideration that all of you have given. Many thanks again and I think the time has come to take time out and work through them. I will post the outcome whatever it is but I have learned so much and have much confidence that this can be resolved. I may be some time.

- - - Updated - - -

SIW2 said:

Is this still going on?

from the screenshot you can see that your bios is picking up disk 0 as first bootable device

therefore detach disk 0 and check it boots into the new os.

If so, reattach disk 0 and mark disk 0 part 1 inactive or swap the bios boot order.



I don't know what that means. Does your bios show drive letters ?

It will not pick up the Win 10 New system to boot since this is not shown in the BIOS screen as a bootable drive. You are right, BIOS does not show drive letters. It is a GUI and shows the bootable drive identified by make but the Win 10 NEW drive is not shown. Therefore it is not bootable.

Thanks to Megahertz for the very complete instructions. I use Macrium Reflect for imaging.
Thanks also to sapakakons and NavyLCDR for your comments.
I feel I have so many suggestions to work through and I am pretty well overwhelmed with the consideration that all of you have given. Many thanks again and I think the time has come to take time out and work through them. I will post the outcome whatever it is but I have learned so much and have much confidence that this can be resolved. I may be some time.

Megahertz said:

@datcoor, your drive 2 (Win new) should boot as it has a active partition and you recreated the path to boot with bcdboot.

I don't understand why you can't boot. Did you try to disconnect drive 0 and 1 (SATA or power cable) to see if it boots from drive 2?

Tell us the story of Win new.
- Did you clone win old or you did a clean install?
- Did it used to boot? If yes, what happen?

The drive NEW is not accessible in BIOS. Since I cannot select it I assume it will not boot. Win NEW was a clone of Win OLD almost a year ago. It was cloned when I decided to use a larger drive. Since then, it has been used continuously. BIOS always showed both drives as selectable boot drives. As described previously, I used the validate command as a test knowing it would fail since there were more than three partitions. The result was that boot information on NEW was wiped and NEW failed to boot. OLD is still available in BIOS and boots OK, hence the ability to run the commands that have been suggested. Almost certainly I will reimage NEW to the state it was in immediately prior to running validate. There is no urgency to update to Win 11. Once I have NEW back. I will disconnect OLD/NEW in turn to carry out the conversion on each. Thank you for your suggestions which I will follow in due course.

Megahertz said:

It may be a BIOS corruption (it has happened on my computer)
As Validate doesn't change anything, don't think a image recovery of NEW to the state it was in immediately prior to running validate will work.
Did you try to disconnect drive 0 and 1 (SATA or power cable) to see if it boots from drive 2?

Thanks, I will check disconnecting drive 0. I thought it unusual that validate would have changed NEW boot config but that's what happened. The other option that I have mentioned is to allow OLD to fully update to 22H2 (it was almost there ) and then clone over as I did in the past.
Just a bit pressed for time at present will update you as and when.

- - - Updated - - -

datcoor said:

Thanks, I will check disconnecting drive 0. I thought it unusual that validate would have changed NEW boot config but that's what happened. The other option that I have mentioned is to allow OLD to fully update to 22H2 (it was almost there ) and then clone over as I did in the past.
Just a bit pressed for time at present will update you as and when.

Megahertz, you were absolutely right. I ran BIOS, still no show for NEW drive, screen shot attached. Disconnected Drive 0, and system booted into NEW, disc map attached showing NEW as system drive. But BIOS still does not show NEW drive, instead it shows drive 0 which is a non system drive. So thanks to NavtLTCDR for bcdboot instructions and you for the disconnect and to all who contributed. There have been so many suggestions I have been reluctant to go charging in with all, just one at a time is better which is why this topic has gone on for so long. Once all is settled down, I will follow the instructions to convert to UEFI, one drive at a time.

If mbr2gpt is being fussy, I would do the job manually with diskgenius. Done it many times, it is quick and doesn't involve unnecessary writes to disk.

Thanks to Megahertz and SIW2 for suggestions which I will digest. I am very very impressed with all those who have contributed to this issue. Just a comment about the BIOS screen. It is too complex and shows drives eg all the UEFI drives, which in fact do not exist. I may do an update of BIOS since clearly it is not showing the correct drive info, so again Megahertz was correct in suggesting BIOS corruption. Since this issue is in a sense resolved I will take time out to implement the conversion by whatever means. But I will come back to this thread with the good news in due course. Thank you all.