[FIXED] MBR2GPT Conversion Failed on Windows

There are various types of error messages you receive when the MBR2GPT fails to convert the disk from MBR to GPT. These errors usually occur when you don’t meet the system requirements and are using an outdated Windows version, a 32-bit Operating System, have more than three partitions, or when Windows doesn’t recognize the partitions on your disk.

The easiest way to solve these errors is by deleting the corrupted data entries, shrinking the disk drive size, or using another tool for the conversion. Following this guide, you will learn how to fix the errors when the system fails to convert MBR2GPT on Windows. 

Disclaimer: Please create a backup of your files and folder with the drive you are working with; if you don’t understand any step in the guide, please ask for recommendations in the comment section before proceeding. We don’t want you to lose all the data in the drive. If you don’t know what you are doing, skip these fixes and use a tool to convert MBR to GPT, we have a detailed guide on converting your MBR partition to GPT without losing data. We won’t be responsible for any data loss or corruption.

Prerequisites: Check system requirements

Before you perform the MBR2GPT conversion on your system, make sure your system meets these requirements. Here are the requirements for using the MBR2GPT Tool:

• You must have Windows 10 version 1703 or higher installed.
• You must have a 64-Bit Windows Operating system.
• The disk you want to convert should be MBR
• The system partition should be active.
• The system should not be in dual boot.
• Windows must recognize each type of Partition on the disk
• The disks should not have extended or logical partitions.
• The front of the disk should be 16KB + 2 sectors and 16KB + 1 sector at the end.
• The disk should not have more than three partitions, including hidden system reserved partitions and recovery partitions.

MBR2GPT Conversion Failed Common Error Codes:

There are multiple error codes that you can face depending on your scenario. We have listed all common error codes below, along with their descriptions and solutions. Follow the steps for the corresponding error code. Here are the error codes that you can face if your MBR2GPT conversion fails:

• Disk layout validation failed for disk 0
• Cannot find OS partition(s) for disk 0
• Cannot Create EFI System Partition Error

Fix: Disk layout validation failed for disk 0

This error occurs when there are more than three partitions or have logical, extended, or dynamic partitions on the disk that interfere with the boot partition count by changing the expected disk number to 0.

Follow the steps below to resolve the following error code.

1. Open the Windows Search box and type “cmd”
2. Right-Click on the Command Prompt and click on “Run as administrator”

   

3. Type the following commands in the command prompt while pressing enter after each command:

   DISKPART 
   LIST DISK
   SEL DISK 0
   LIST PART

4. If you have more than one disk, select the one you want to delete. (We have selected DISK 0 as a demonstration, you don’t need to choose DISK 0, instead, select the one you want to delete). 
5. If there are more than three partitions, delete one Partition. But make sure to create a backup copy of the Partition.

   

6. Right-Click on your This PC and click on the manage option
7. Select the Disk Management option on the left side of the panel in the Storage section

   

8. Right-Click on the Partition, you want to delete by selecting the “Delete Volume” option. 
9. Click on YES 

   

10. If the Partition says “Free Space,” right-click on it again and click on “Delete Partition.”
11. Open the Command Prompt Window to delete the Partition.
12. Type in the following command with the partition number you want to delete:

    SEL PART 4
    DELETE PART
    LIST PART

13. Type EXIT to close the disk part and type in the following command to convert MBR to GPT without losing data:

    MBR2GPT /ALLOWFULLOS CONVERT

Fix: Cannot find OS partition(s) for disk 0

This error occurs when MBR2GPT cannot detect the OS Partition for Disk 0. The primary reason for this error is the Invalid entries in the boot configuration data. This error can also occur if you are selecting the drive that doesn’t have Windows installed.

To fix this error, follow the steps given below:

1. Search for the Command Prompt on Windows Search Bar and run it as an administrator.

   

2. Type in the following command to check the Partition where the OS is installed and the Partition which is reserved by the system:

   diskpart
   sel par 2
   assign letter = W
   sel par 1
   assign letter = B
   exit

3.  The next step is checking the files in the Windows partition by typing the following command:

   dir /a W:\

4. If you fail to find any boot folder inside the Windows partition, then shift to the system-reserved one by typing the following commands:

   dir /a B:\

5. If you found the boot folder in the system-reserved Partition, then type in the following command:

   dir /a B:\Boot

6. To look for any Invalid entries, type the following command to find the entry with the name “Unknown,” which indicates that the entry has been corrupted:

   bcdedit /store B:\boot \BCD /enum all

7. The invalid entry will most likely be found in the Windows Boot Loader. Delete the entry by copying its Identifier name and pasting it with the boot configuration data edit, for example:

   bcdedit /store B:\boot \bcd /delete {9ab65a10-e032-11ea-9be5-c7044420cc92}

Fix: Cannot Create EFI System Partition Error

If you are facing the “Cannot Create EFI System Partition” Error, the best option is to free up some space on your drive and create the required unallocated space on your disk.

You can do this by following the method below:

1. Right-Click on your MyPC and open the manage option. 
2. Click on the Disk Management option on the left side in the Storage section.

   

3. Right-Click on the DISK 0 Drive where you want to create an unallocated space and select the “Shrink Volume” option. 

   

4. In the “Enter the amount of space to shrink in MB” section, type in the number you want the disk to shrink, and press the Shrink Button. 

   

5. Run the command prompt as an administrator and type in the following command to create an EFI System Partition:

   DISKPART
   LIST DISK
   SELECT DISK 1
   CREATE PARTITION EFI
   EXIT 

Perform MBR2GPT Conversion using another Tool

If you are still facing any conversion error with the MBR2GPT, then it is best to use an alternate method by using another tool for this process. One such Tool is the MiniTool Partition Wizard. This Tool can convert MBR to GPT without damaging your data files. The best part is that it can be used for both system and non-system disks. However, ensure that you use a Pro or higher edition of Windows with a 64-bit Operating System. 

Below are the steps to download the MiniTool Partition Wizard on your system:

1. Open the MiniTool Partition Wizard and look for the disk still using MBR.
2. Right-Click on the target disk and select the “Convert MBR to GPT disk” option.

   

3. Click on OK, and apply the changes.
4. Since the Operating system is in the affected drive, you must click on “Restart Now” to restart your computer. 
5. Once the system restarts, you must open your BIOS and enable UEFI Boot Mode.
6. Once your system has started, it will have converted the targeted disk from MBR2GPT with no data loss.