Windows 10: Convert Windows 10 from Legacy BIOS to UEFI without Data Loss

1) user should make an image backup or backup valuable data as a minimum.

2) you should always run validate option first.

 

Agreed.

The conversion process will include validating before it actually converts though.

 

I finally managed to do the conversion. Here is a summary:

MBR disk: 4 partitions. SRP with WinRE, OS, extended with two logical data partitions.

First try failed. Error: two partitions not recognized. The procedure found 6 partitions (not 4). The problem was related to the extended partition.

I converted the 2 logicals to primaries. Now 4 primary partitions in the disk.

Second try, also failed. Error: Too many MBR partitions.

I deleted the last data partitions (a small one, easy to recover). Now 3 primary partitions in the disk.

After this, the disk layout validated OK, the conversion was a success.

GPT disk: Recovery, EFI, OS, data partition.

The WinRe is enabled.

 

Hi. I can't even validate using the mbr2gpt tool. I am getting an "Unrecognized partition found" error.




The setuperr and setupact log files are attached too. Somebody please hep. *Smile

Setuperr:
Code: 2017-04-23 21:15:05, Error ValidateLayout: Unrecognized partition found, index 2 2017-04-23 21:15:05, Error Disk layout validation failed for disk 0[/quote] setupact:
Code: 2017-04-23 21:15:05, Info MBR2GPT was explicitly asked to run in full OS mode.2017-04-23 21:15:05, Info MBR2GPT: System disk number is 0 2017-04-23 21:15:05, Info MBR2GPT: Attempting to validate disk 0 2017-04-23 21:15:05, Info MBR2GPT: Retrieving layout of disk 2017-04-23 21:15:05, Info MBR2GPT: Initial partition information 2017-04-23 21:15:05, Info =========================================================== 2017-04-23 21:15:05, Info Partition layout for disk: 0 2017-04-23 21:15:05, Info Partition style : MBR 2017-04-23 21:15:05, Info MBR signature: 1827330867 2017-04-23 21:15:05, Info Number of partitions : 4 2017-04-23 21:15:05, Info ===================PARTITION=============================== 2017-04-23 21:15:05, Info Number: 1 2017-04-23 21:15:05, Info Type: 7 2017-04-23 21:15:05, Info Boot: Yes 2017-04-23 21:15:05, Info Recognized: Yes 2017-04-23 21:15:05, Info Style: 0 2017-04-23 21:15:05, Info Offset: 1048576 2017-04-23 21:15:05, Info Length: 524288000 2017-04-23 21:15:05, Info Volume: \\?\Volume{6ceadb33-0000-0000-0000-100000000000}\ 2017-04-23 21:15:05, Info Drive: None 2017-04-23 21:15:05, Info NT Path: \Device\HardDisk0\Partition1 2017-04-23 21:15:05, Info ===================PARTITION=============================== 2017-04-23 21:15:05, Info Number: 2 2017-04-23 21:15:05, Info Type: 7 2017-04-23 21:15:05, Info Boot: No 2017-04-23 21:15:05, Info Recognized: Yes 2017-04-23 21:15:05, Info Style: 0 2017-04-23 21:15:05, Info Offset: 525336576 2017-04-23 21:15:05, Info Length: 107467505664 2017-04-23 21:15:05, Info Volume: \\?\Volume{6ceadb33-0000-0000-0000-501f00000000}\ 2017-04-23 21:15:05, Info Drive: C:\ 2017-04-23 21:15:05, Info NT Path: \Device\HardDisk0\Partition2 2017-04-23 21:15:05, Info ===================PARTITION=============================== 2017-04-23 21:15:05, Info Number: 0 2017-04-23 21:15:05, Info Type: 15 2017-04-23 21:15:05, Info Boot: No 2017-04-23 21:15:05, Info Recognized: No 2017-04-23 21:15:05, Info Style: 0 2017-04-23 21:15:05, Info Offset: 107993889792 2017-04-23 21:15:05, Info Length: 892209202176 2017-04-23 21:15:05, Info Volume: <unknown>, Error:0x00000012 2017-04-23 21:15:05, Info Drive: None 2017-04-23 21:15:05, Info NT Path: \Device\HardDisk0\Partition0 2017-04-23 21:15:05, Info ===================PARTITION=============================== 2017-04-23 21:15:05, Info Number: 3 2017-04-23 21:15:05, Info Type: 7 2017-04-23 21:15:05, Info Boot: No 2017-04-23 21:15:05, Info Recognized: Yes 2017-04-23 21:15:05, Info Style: 0 2017-04-23 21:15:05, Info Offset: 107993890816 2017-04-23 21:15:05, Info Length: 892209201152 2017-04-23 21:15:05, Info Volume: \\?\Volume{6ceadb33-0000-0000-0000-f02419000000}\ 2017-04-23 21:15:05, Info Drive: E:\ 2017-04-23 21:15:05, Info NT Path: \Device\HardDisk0\Partition3 2017-04-23 21:15:05, Info =========================================================== 2017-04-23 21:15:05, Info ESP partition size will be 104857600 2017-04-23 21:15:05, Info MBR2GPT: Validating layout, disk sector size is: 512 bytes 2017-04-23 21:15:05, Error ValidateLayout: Unrecognized partition found, index 2 2017-04-23 21:15:05, Error Disk layout validation failed for disk 0[/quote]

 

The process does not work with logical partitions. You can convert the logical to primary with MiniTool Partition Wizard Free.

Or, you can delete the logical and restore it from a backup after the conversion.

 

hello bro i am new to fourm. can you please explain this command again for me

reagentc /setreimage /path \\?\GLOBALROOT\device\harddisk0\partition3\Recovery\WindowsRE

i have two partitions so i write partition 2 instead of 3 and come up with an error
REAGENTC.EXE: The specified path was not found.

 

Try this method but no success. And also usb media already contains install.wim file of about 3.5 gb.


PS C:\WINDOWS\system32> REAGENTC /SetOSImage /Path C:\Win10-Recovery\INSTALL.WIM /Index 1Directory set to: \\?\GLOBALROOT\device\harddisk0\partition1\Win10-RecoveryREAGENTC.EXE: Operation Successful.PS C:\WINDOWS\system32> REAGENTC /InfoWindows Recovery Environment (Windows RE) and system reset configurationInformation: Windows RE status: Disabled Windows RE location: Boot Configuration Data (BCD) identifier: 42d7ea6a-31f3-11e7-a748-fa207b40608d Recovery image location: \\?\GLOBALROOT\device\harddisk0\partition1\Win10-Recovery Recovery image index: 1 Custom image location: Custom image index: 0REAGENTC.EXE: Operation Successful.PS C:\WINDOWS\system32> mbr2gpt /convert /allowfullOSMBR2GPT will now attempt to convert the default book disk.If conversion is successful the disk can only be booted in GPT mode.These changes cannot be undone!MBR2GPT: Attempting to convert disk 0MBR2GPT: Retrieving layout of diskMBR2GPT: Validating layout, disk sector size is: 512 bytesCannot find OS partition(s) for disk 0PS C:\WINDOWS\system32>

 

Sir i manage to boot to uefi using this command. But during conversion there is one command missing please see image. So i want to know that is the conversion is sucessfully placed or not?

 

Hello @gurgurdeep, *Smile

I don't see anything missing in your screenshot. It looks like it has successfully converted to UEFI.

You will need to boot to your UEFI firmware settings, and switch the firmware to boot to UEFI mode instead of Legacy BIOS (CSM) to finish.

 

Ya already done that. Thanks for procedure.

 

Just to make sure:
Motherboard: X99

Currently: Windows 10 x64 15063.296
Legacy BIOS.




2 SSD's and multiple HDD's

1st SSD is Disk 1 = Windows
2nd SSD is Disk 2

rest are HDD's
Disk 0 is also MBR
Disk 7 is an encrypted container





Questions:
- should I convert all 3 MBR disks?
- in case I convert disk 2, (containing Windows) how will it then handle the reserved unallocated SSD space ?
Assume it will remain untouched.
- on disk 3 (SSD) obviously there is also a reserved space
- should I run two separate commands

a) MBR2GPT /validate /disk:2 /logs:d:\
and then
b) MBR2GPT convert /disk:2 /logs:d:\ /allowFullOS

or
MBR2GPT convert /disk:2 /logs:d:\ /allowFullOS /validate

Thanks!
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Hello @tfwul, *Smile

You can run the command below in an elevated command prompt while in Windows to validate and see if it will be able to convert your Windows installation to UEFI or not.

mbr2gpt /validate /allowFullOS

If it says it's able to, then you can run the command below to convert.

mbr2gpt /convert /allowfullOS

 

Thanks again. BTW, as always, the very last thing before applying upgrades is creating a image (Macrium), so I can always revert to a working Windows. I wonder, images created in the legacy BIOS/MBR mode, would it be possible to restore them after conversion.
Really wouldn't know.

Assume media creation tool will not be able create a UEFI USB thumbdrive?
(I need Rufus for that?)
or will mediacreation tool 'see/recognize' an UEFI system and then thus create an UEFI USB thumbdrive.


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Creating a Macrium image first would be a good idea. If you should need to restore it, it'll restore it back to how it was when the image was created.

You don't need installation media to do this conversion, but it would be handy to have in the future though. You can use any option below to create a UEFI USB.

Create Bootable USB Flash Drive to Install Windows 10 Windows 10 Installation Upgrade Tutorials

 

I will do this conversion once I know .. if.., and if so, where and what exactly I also need to change in the BIOS of my Asus x99 DeLuxe/U3.1
It seems I should go into the BIOS settings as well and should change 'something, somewhere in some screen'. Have spent quite a bit of time trying to figure this out.

I'll continue searching.

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