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Dell, Win 10 MBR convert failure


Dell MBR system disk fails to convert to GPT

Failure to convert layout 0x00000000

Dell OEM partition is present.

Dell OEM partition uses partition type 0xDE (222 decimal)

Custom Dell Recovery partition does not contain sufficient free space to complete conversion


<--------------- DISK LAYOUT  -------------------->

[ OEM Fat15 (Dell type OxDE, 222) 39MB ]

[ RECOVERY NTFS (Active, Primary) 10GB ]

[C: WINDOWS NTFS (Boot, Page, Crash Dump, Basic) 110GB ]


Fault: mbr2gpt validates conversion to GPT but when the conversion is attempted the operation fails and EFI partition creation is rolled back. %windir%\setuperr.log may report partition type 222 can not be identified and must be manually mapped.

The fault is caused by Windows failing to recognise the OEM partition type.

To rectify

1. Use GParted (Linux) to delete the OEM partition.

2. Complete the GPT2MBR conversion

3. Set BIOS to EUFI boot

4. Add the Windows Boot Manager option with path \EFI\Microsoft\Boot\Bootmgfw.efi

5. Assign a drive letter to the recovery partition (for instance R:)

6. REAGENTC /setwinre /path r:/recovery/WinRE


Additional fixes that may be required

The Dell custom recovery partition may have insufficient space to complete the GPT/EFI conversion. Deleting .wim image files from the partition does not free space in the file system.

1. Shrink the Windows partition by 1GB

2. Use Gparted (Linux) to move the Windows partition to the end of the disk

3. Extend the Recovery partition


Other log files implicated by mbr2gpt

%windir%\setupact.log, diagerr.xml, and diagwrn.xml


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Article details
Article ID: 135
Category: Windows
Date added: 10-09-2020 12:54:03
Views: 61
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