Question Convert MBR to GPT with OS and data in tact

[stevwolf]

I want to convert and existing windows 10 to GPT so I can use uefi bios

I tried using mbr2gpt /validate then mbr2gpt /convert but failed I want to try again. I have cleaned up some stuff on the disk.
However i contacted my backup company because I was having problems restoring back to original to try again, and they gave me this advice.

---- snip ---
If you need to change Windows disk partition style, best approach will be to copy/back up your important data elsewhere, and reinstall Windows from scratch, on newly-partitioned disk.

You can also use the following workaround:

1 Create a backup of Whole Disk (C: and other partitions, if needed)
2 Convert the disk to GPT, destroying all partitions
3 Boot Windows installation in uEFI mode, and allow it to create the required partitions
4 Restore C: partition from the backup over freshly-installed Windows C: partition, and other partitions (if needed), separately
5 Perform fixup procedures from Recovery Partition if needed.
--- end --

However I'm confused, I thought that the mbr2gpt was to do exactly what I need, I have mbr and want to convert it to GPT. It seems many people have done this and it works.
while there may be better ways, am I wrong that using mbr2gpt doesnt takes into consideration that you have mbr when I thought thats the point of the program ??

Regards

 

[DSzymborski]

Is the data not properly backed up? If not, that's a far more pressing and troubling issue than converting your drive.

 

[USAFRet]

I tried using mbr2gpt /validate then mbr2gpt /convert but failed I want to try again.

In what way did it fail?

I absolutely would not do or continue with this without a known good backup, preferably a full drive backup of the entire thing.

 

[MrLitschel]

Check out Microsoft Page for using Mbr2GPT, It will definately help on why it failed: https://docs.microsoft.com/en-us/windows/deployment/mbr-to-gpt

Four log files are created by the MBR2GPT tool:

• diagerr.xml
• diagwrn.xml
• setupact.log
• setuperr.log

These files contain errors and warnings encountered during disk validation and conversion. Information in these files can be helpful in diagnosing problems with the tool. The setupact.log and setuperr.log files will have the most detailed information about disk layouts, processes, and other information pertaining to disk validation and conversion. (Note: the setupact*.log files are different than the Windows Setup files that are found in the %Windir%\Panther directory. )

 

[stevwolf]

Well I did a restore from another machine to get it up and running. As all issues there are many. I have struggled for several days on this, any way I have not been able to backup this computer using paragon-disk manager. It backs it up and all the files are in t he backup but then when you try to restore you get disk not valid. I have run every test ther on the test and it seems good. Chkdsk /f /r /x Sfc /verifyonly/ sfc /scannow dism /online /clean-image /checkhealth dism /online /clean-image /scanhealth dism /online /clean-image /restorehealth still it gives error Disk not Valid, HOWEVER, I may have solve this. I was backing up to a 5 TB drive. I actually think that the error was coming from the 5 TB USB drive not the 250 GB windows drive. I did a backup to a 150GB drive and I got no error when verifying. Does that make sense, that is that it cant properly backup to a drive bigger than 2 TB because its not GPT ??

So what errors did i get when I did the convert you ask ??

Well I think it actually worked with one error ?

It said "Conversion completed successfully" Then it said
MBR2GPT: Conversion completed successfullyCall WinReReapir to repair WinRE
MBR2GPT: Failed to update ReAgent.xml, please try to manually disable and enable WinRE.
MBR2GPT: Before the new system can boot properly you need to switch the firmware to boot to UEFI mode!

So then I rebooted and it did not boot. However one place I may have gone wrong is I was in a dos window when the conversion finished and maybe it wanted me at THAT time to fix the issue with repair command. I was unfamiliar with the various commands like reagentc . When you have never done this before your overwhelmed and make mistakes. Despite trying to read what I could.

So I think I have a good backup but not sure how to proceed again? I would like to use the mbr2gpt as I think it is the simplest.
Regards

 

[SkyNetRising]

So I think I have a good backup but not sure how to proceed again? I would like to use the mbr2gpt as I think it is the simplest.

Can you show screenshot from Disk Management?
(upload to imgur.com and post link)

 

[stevwolf]

Check out Microsoft Page for using Mbr2GPT, It will definately help on why it failed: https://docs.microsoft.com/en-us/windows/deployment/mbr-to-gpt

Four log files are created by the MBR2GPT tool:

• diagerr.xml
• diagwrn.xml
• setupact.log
• setuperr.log

These files contain errors and warnings encountered during disk validation and conversion. Information in these files can be helpful in diagnosing problems with the tool. The setupact.log and setuperr.log files will have the most detailed information about disk layouts, processes, and other information pertaining to disk validation and conversion. (Note: the setupact*.log files are different than the Windows Setup files that are found in the %Windir%\Panther directory. )

Thank you for you information. I will look at it. Of course if the system doesn't boot its hard to see those files. But maybe I could look at them before it boots?

 

[stevwolf]

Can you show screenshot from Disk Management?
(upload to imgur.com and post link)

Hopefully this works .. and this is what you are looking for.

https://imgur.com/t76WRm2

View: https://imgur.com/t76WRm2