Master Boot Record (MBR) and GUID Partition Table (GPT) are distinct partitioning schemes in the Windows operating system. MBR accommodates volumes up to 2TB and files as large as 4GB, whereas GPT supports up to 9.4 Zettabytes and 128 primary partitions. MBR is compatible with BIOS, whereas GPT works with UEFI. Consequently, some users may wish to convert from MBR to GPT, only to encounter the issue of "can't convert MBR to GPT."

Whether it's changing firmware from BIOS to UEFI or preparing to upgrade from Windows 10 to Windows 11, converting MBR to GPT is necessary. Let's delve into the details of the "can't convert MBR to GPT" error. We'll discuss the main reasons behind it and then proceed with the top three methods to resolve this issue.

Why Can't Convert MBR to GPT?

Before diving into the solutions for "can't convert MBR to GPT, it's crucial to understand the top reasons behind this issue. Among various possible causes, the existing partitions on the disk might pose problems during the MBR to GPT conversion. The Disk Management tool can only convert an empty non-system disk.

Therefore, before opting for a disk management tool that doesn't support converting MBR to GPT, it's crucial to back up all essential data on the disk. You need to delete all partitions beforehand, and then initiate the MBR to GPT conversion process. Once all partitions are erased, the option to convert from MBR to GPT will no longer be disabled or grayed out.

Open Disk Management

How to Resolve "Windows Cannot Convert MBR to GPT" Error

Upon examining the primary reasons why disk management cannot convert MBR to GPT, we arrive at the top solutions to address this issue. Here are the top three methods to fix this problem:

  1. Method 1. Convert MBR to GPT using Partition Master (Without Data Loss)
  2. Method 2. Convert to GPT via Disk Management (Requires Deleting All Partitions)
  3. Method 3. Convert MBR to GPT with Diskpart (Data Loss Expected)

It is advisable to opt for the first approach, which involves converting MBR to GPT without any data loss. However, if users choose to convert to GPT by deleting all partitions or transform MBR to GPT with data loss, it is crucial to create a backup first. Ensuring a proper data backup prevents users from unforeseen data loss scenarios. Now, let's examine each of these three methods in detail.

Method 1: Convert MBR to GPT Without Data Loss

tools Partition Master is the ideal solution for seamlessly converting MBR to GPT without any data loss. Users who wish to transition from the traditional MBR to the advanced GPT format can utilize the tools Partition Master for a swift conversion process. Furthermore, the same tool enables you to convert back from GPT to MBR if needed. tools Partition Master also aids in cloning system partitions and swiftly converting NTFS to FAT32. By employing this tool, readers can effortlessly convert MBR to GPT without compromising their data.

Steps to use the tool Partition Master: 1. Download and Install: First, download the Partition Master software from a reliable source. Once downloaded, run the installation file and follow the on-screen instructions to install it on your computer. 2. Launch the Software: After installation, locate the Partition Master icon on your desktop or in the Start menu and double-click it to launch the program. 3. Interface Overview: Upon opening, you'll see a user-friendly interface with a graphical representation of your hard disk partitions. It will display all the drives connected to your system. 4. Select Partition: Identify the partition you want to work with. You can choose between primary, extended, or logical partitions. The software will highlight the selected partition. 5. Choose an Action: Partition Master offers various actions such as resize, move, create, delete, format, and check partitions. Click on the desired action button located on the top menu or right-click the partition and select the option from the context menu. 6. Perform the Operation: - Resize/Move: Drag the partition edges left or right to increase or decrease its size. Alternatively, input the new size manually. Click "Apply" or "OK" to execute the changes. - Create: Select an unallocated space and specify the size for the new partition. Choose the file system (e.g., NTFS, FAT32) and allocation method. Then, click "Create." - Delete: Right-click the partition you wish to delete and select "Delete." Confirm the deletion prompt. - Format: Right-click the partition and choose "Format." Select the file system, allocation unit size, and give a volume label if needed. Click "OK." - Check: This option helps to verify the integrity of the partition. Right-click and select "Check." 7. Review Changes: Before applying any changes, review the proposed layout in the software's preview window. Ensure that the adjustments meet your requirements. 8. Apply Changes: If satisfied, click the "Execute Operations" or "Apply" button to start the process. The software will warn you that the operation may take time and require a reboot. 9. Wait for Completion: The tool will now execute the chosen operations. This may take some time depending on the size of the partitions and the speed of your system. Do not interrupt the process. 10. Verify Results: After the completion, restart your computer, and the new partition layout should be reflected in your system. Use Windows Explorer or Disk Management to confirm the changes. Remember, always back up important data before making any significant changes to your partitions to avoid potential data loss.

Step 1. Download and launch tools Partition Master on your computer.

Step 2. Proceed to Disk Converter, choose "Convert MBR to GPT," and click "Next" to proceed.

convert MBR to GPT - 1

Step 3. Select the target MBR disk that you intend to convert to GPT, and click "Convert" to start the process.

convert MBR to GPT - 2

Method 2: Convert to GPT Without Deleting All Partitions

The process of converting to GPT typically involves deleting existing partitions. One straightforward approach is to use the Disk Management utility to alter the Master Boot Record (MBR) to the GUID Partition Table (GPT). Disk Management tools are specialized software utilities designed to manage disk data with various functions. They enable efficient partitioning of devices, management of drives, bootable formatting of disks, and provide disk checking capabilities.

The swift steps to convert to GPT by erasing all partitions via Disk Management are as follows:

Step 1. Go to the "Manage" option in "This PC" and select "Disk Management."

Step 2. Open the target MBR disk and delete each partition by selecting "Delete Volume."

Step 3. Click "OK" to confirm the volume deletion.

Step 4. Repeat steps 2 and 3 until all the different disk volumes are deleted correctly.

Step 5. After deleting all disk volumes, the entire disk should appear as unallocated. Right-click on the MBR disk and choose "Convert to GPT Disk."

convert to gpt disk using disk management

Step 6. Close the Disk Management option once the disk conversion process is complete.

Method 3: Convert MBR to GPT with Data Loss

Lastly, we're gonna talk about converting MBR to GPT with minimal data loss using Diskpart. Diskpart is a specialized command interpreter that aids in professional disk management on computers. It handles stuff like disk partitions, volumes, and virtual hard disks. To use it, just type "diskpart" in the Command Prompt on any system. It's a command-line tool that lets you perform actions like creating partitions, deleting partitions, formatting, extending volumes, assigning or removing drive letters, and more.

The rapid steps to convert MBR to GPT with data loss using the DiskPart utility are:

Step 1. Create a backup of the entire disk before launching DiskPart. This is crucial because using DiskPart will erase all data from the partition.

Step 2. Go to the "Start" menu and type "cmd."

type CMD

Step 3. Right-click on "Command Prompt" and select "Run as administrator."

Step 4. Type "diskpart" and press Enter. If prompted for permission, click "Yes."

Step 5. Enter the following commands one by one and press Enter after each:

    1. list disk 2. select disk 2 (Replace '2' with the disk number of the MBR disk) 3. clean 4. convert gpt

Step 6. It will delete all the partitions on the disk and then convert them to GPT.

MBR to GPT conversion

Step 7. Type "exit" once the conversion process is finished.

Conclusion

I hope it's now clear to our readers about the quick solutions for the issue of unable to convert MBR to GPT. Both beginners and professionals should now understand why the disk management tool is not allowing the conversion from MBR to GPT. The main reason for the conversion option being grayed out is typically related to disk partition issues. Disk Management can only convert MBR to GPT when the disk is completely empty.

The various approaches to address the issue of "Windows can't convert MBR to GPT" include converting MBR to GPT without data loss, converting to GPT by deleting all partitions, and converting MBR to GPT with data loss. It is advisable to opt for converting MBR to GPT without data loss.

FAQs: Unable to Convert MBR to GPT 1. What is MBR and GPT? - MBR (Master Boot Record) is an older disk partitioning scheme, while GPT (GUID Partition Table) is a modern replacement that supports larger disks and offers better resilience. 2. Why do I need to convert MBR to GPT? - Converting to GPT is necessary for utilizing the full capacity of large hard drives, supporting more than four primary partitions, and ensuring better compatibility with UEFI-based systems. 3. Can I convert MBR to GPT without losing data? - Yes, but it requires using specialized software and following specific steps carefully. Be sure to back up important data before attempting any conversion. 4. How can I convert MBR to GPT in Windows? - You can use the built-in Disk Management tool in Windows 10/8/7 after backing up your data, or third-party tools like tools Partition Master, MiniTool Partition Wizard, or AOMEI Backupper. 5. What are the risks of converting MBR to GPT? - The main risk is potential data loss if the conversion process fails or is not done correctly. Additionally, some older BIOS-based systems may not support GPT. 6. Will my operating system still work after converting MBR to GPT? - If you're using a modern OS like Windows 10, it should work seamlessly. However, older operating systems may require a reinstallation. 7. Can I convert GPT back to MBR if needed? - Yes, but again, this involves data loss. Ensure you have backups before reverting. 8. Is it necessary to convert both the system drive and data drives to GPT? - Only the system drive needs to be converted to GPT for UEFI booting. Data drives can remain MBR if desired. 9. How long does the MBR to GPT conversion process take? - The time varies depending on the size of your disk and the speed of your computer. It can range from a few minutes to several hours. 10. Do I need to update my BIOS or firmware after converting to GPT? - If you're transitioning from BIOS to UEFI, updating your firmware might be necessary for optimal system compatibility and performance.

After reading the comprehensive article on "can't convert MBR to GPT," you might have some queries. Here's a concise list of frequently asked questions that can aid in enhancing your understanding of the subject:

1. How do I activate the conversion to GPT?

The swift steps to enable conversion to GPT are:

Step 1. Prepare a GPT disk.

Step 2. Download the Windows 10 ISO and create a Windows Installation Media on a USB drive.

Step 3. Set the PC Boot Mode to UEFI and boot from the USB drive.

Step 4. Begin and complete the installation of Windows 10 on the GPT disk partition.

Step 5. Restart the PC and set Windows to boot from the new GPT partition.

Step 6. Activate Windows 10.

2. Why is "Convert to MBR" greyed out?

The conversation with MBR may become grayed out due to the presence of multiple partitions on the selected MBR disk. The disk management tool is capable of converting GPT to MBR only for an empty disk.

3. Why can't I convert my hard drive to GPT? There could be several reasons why you're unable to convert your hard drive to the GUID Partition Table (GPT) format. Here are some common issues and their possible solutions: 1. **Windows Operating System Limitations:** - In Windows, you cannot directly convert a Basic Disk with an existing operating system (OS) from the Master Boot Record (MBR) to GPT without data loss. You'll need to back up your data, reformat the drive, and reinstall the OS. 2. **Using Disk Management Utility:** - If you're using the built-in Windows Disk Management tool, it doesn't have an option to convert directly. Instead, you can use third-party tools like AOMEI Partition Assistant or MiniTool Partition Wizard. 3. **Secure Boot and UEFI Settings:** - Some systems require Secure Boot and UEFI mode to boot from a GPT disk. Ensure that your BIOS/UEFI settings support these features and are correctly configured. 4. **Partition Layout:** - MBR disks have a maximum of four primary partitions, while GPT allows up to 128. If your disk is already fully partitioned, you might need to delete or resize partitions before converting. 5. **Hardware or Software Compatibility:** - Some older hardware or software may not support GPT. Check if your system and all essential software are compatible with GPT. 6. **Bootable Media:** - If you're trying to convert a boot drive, you'll need a bootable media with the conversion tool to perform the operation outside of the current OS. To convert to GPT, follow these general steps: 1. Back up all important data. 2. Boot from a bootable media with a conversion tool. 3. Delete existing partitions on the target drive. 4. Convert the drive to GPT using the tool. 5. Reinstall the OS, if necessary, ensuring to boot in UEFI mode. Always exercise caution when dealing with disk conversions, as data loss can occur if not done properly.

The challenges in converting the hard drive to GPT arise from the existing partitions on the disk. The Disk Management utility can convert an empty non-system disk from MBR to GPT or vice versa. However, if there are existing partitions, especially system partitions, additional steps or specialized tools may be required to ensure data integrity and successful conversion.