Convert the partition table

Oct 13, 2025 by wbrum.org 102 views

Unable to Boot Windows 10 After Converting from MBR to GPT: A Step-by-Step Solution

Discussion Category: Boot, UEFI

Additional Information:

For Windows 11 preparation, converting your hard disk drive (HDD) to a GUID Partition Table (GPT) on a Windows 10 system is a common practice. However, this process can be challenging, and users often encounter issues after the conversion. In this article, we will discuss a common problem where the HDD does not show up under UEFI boot devices after converting from MBR to GPT.

Understanding the Conversion Process

Before we dive into the solution, it's essential to understand the conversion process from MBR to GPT. The Master Boot Record (MBR) is a type of partition table used by older operating systems, while the GUID Partition Table (GPT) is a newer, more advanced partition table used by modern operating systems, including Windows 10 and Windows 11.

The conversion process involves the following steps:

Backup your data: Before converting your HDD to GPT, it's crucial to backup your important files and data to an external drive or cloud storage.
Use a third-party tool: You can use a third-party tool, such as EaseUS Partition Master or AOMEI Partition Assistant, to convert your HDD to GPT.
Convert the partition table: The tool will convert the MBR partition table to a GPT partition table.
Reboot your system: After the conversion, your system will automatically reboot.

The Problem: HDD Does Not Show Up Under UEFI Boot Devices

After converting your HDD to GPT, you may encounter an issue where the HDD does not show up under UEFI boot devices. This can be frustrating, especially if you're trying to prepare your system for Windows 11.

Causes of the Problem

There are several reasons why your HDD may not show up under UEFI boot devices after converting from MBR to GPT:

Incorrect UEFI settings: Your UEFI settings may be misconfigured, preventing your HDD from showing up under UEFI boot devices.
Corrupted UEFI firmware: Corrupted UEFI firmware can cause issues with booting from a GPT partition table.
Incompatible UEFI firmware: Some UEFI firmware versions may not be compatible with GPT partition tables.
Incorrect partition table configuration: The partition table configuration may be incorrect, preventing your HDD from showing up under UEFI boot devices.

Solutions to the Problem

To resolve the issue, follow these steps:

Step 1: Check UEFI Settings

Enter UEFI settings: Restart your system and enter UEFI settings by pressing the corresponding key (usually F2, F12, or Del).
Check boot order: Ensure that your HDD is set as the first boot device in the UEFI boot order.
Save changes: Save the changes and exit UEFI settings.

Step 2: Update UEFI Firmware

Check for updates: Check with your motherboard manufacturer for any UEFI firmware updates.
Update UEFI firmware: If an update is available, download and install it.
Reboot your system: After updating UEFI firmware, reboot your system.

Step 3: Reconfigure Partition Table

Use a third-party tool: Use a third-party tool, such as EaseUS Partition Master or AOMEI Partition Assistant, to reconfigure the partition table.
Reconfigure GPT partition table: Reconfigure the GPT partition table to ensure that it is correctly configured.
Reboot your system: After reconfiguring the partition table, reboot your system.

Step 4: Check for Incompatible UEFI Firmware

Check UEFI firmware version: Check the version of your UEFI firmware.
Check compatibility: Check if your UEFI firmware version is compatible with GPT partition tables.
Update UEFI firmware: If your UEFI firmware version is not compatible, update it to a compatible version.

Step 5: Reinstall Windows 10

Backup your data: Before reinstalling Windows 10, backup your important files and data to an external drive or cloud storage.
Reinstall Windows 10: Reinstall Windows 10 on your system.
Reconfigure UEFI settings: Reconfigure UEFI settings to ensure that your HDD is set as the first boot device.

Conclusion

Converting your HDD to GPT on a Windows 10 system can be challenging, and users often encounter issues after the conversion. In this article, we discussed a common problem where the HDD does not show up under UEFI boot devices after converting from MBR to GPT. We provided step-by-step solutions to resolve the issue, including checking UEFI settings, updating UEFI firmware, reconfiguring the partition table, checking for incompatible UEFI firmware, and reinstalling Windows 10. By following these steps, you should be able to resolve the issue and successfully boot from your HDD after converting from MBR to GPT.
Frequently Asked Questions (FAQs) About Converting from MBR to GPT

Discussion Category: Boot, UEFI

Additional Information:

Converting from MBR to GPT can be a complex process, and users often have questions about the conversion process. In this article, we will answer some frequently asked questions (FAQs) about converting from MBR to GPT.

Q: What is the difference between MBR and GPT?

A: Master Boot Record (MBR) is a type of partition table used by older operating systems, while GUID Partition Table (GPT) is a newer, more advanced partition table used by modern operating systems, including Windows 10 and Windows 11.

Q: Why do I need to convert from MBR to GPT?

A: You need to convert from MBR to GPT to take advantage of the benefits of GPT, such as:

Support for larger disk sizes: GPT can support larger disk sizes than MBR.
Improved reliability: GPT is more reliable than MBR and can recover from errors more easily.
Better support for modern operating systems: GPT is required by modern operating systems, including Windows 10 and Windows 11.

Q: How do I convert from MBR to GPT?

A: To convert from MBR to GPT, you can use a third-party tool, such as EaseUS Partition Master or AOMEI Partition Assistant. Follow these steps:

Backup your data: Before converting your HDD to GPT, backup your important files and data to an external drive or cloud storage.
Use a third-party tool: Use a third-party tool to convert your HDD to GPT.
Reboot your system: After the conversion, reboot your system.

Q: What are the risks of converting from MBR to GPT?

A: The risks of converting from MBR to GPT include:

Data loss: If you don't backup your data before converting, you may lose your important files and data.
System instability: Converting from MBR to GPT can cause system instability, especially if you have multiple operating systems installed.
UEFI firmware issues: Converting from MBR to GPT can cause issues with UEFI firmware, especially if you have an older UEFI firmware version.

Q: How do I check if my UEFI firmware is compatible with GPT?

A: To check if your UEFI firmware is compatible with GPT, follow these steps:

Check UEFI firmware version: Check the version of your UEFI firmware.
Check compatibility: Check if your UEFI firmware version is compatible with GPT partition tables.
Update UEFI firmware: If your UEFI firmware version is not compatible, update it to a compatible version.

Q: Can I convert from GPT to MBR?

A: Yes, you can convert from GPT to MBR, but it's not recommended. Converting from GPT to MBR can cause data loss and system instability.

Q: How do I recover from a failed conversion from MBR to GPT?

A: If you experience issues after converting from MBR to GPT, follow these steps:

Reboot your system: Reboot your system and try to boot from a different device.
Use a recovery disk: Use a recovery disk to recover your system.
Seek professional help: If you're unable to recover your system, seek professional help from a qualified technician.

Conclusion

Converting from MBR to GPT can be a complex process, and users often have questions about the conversion process. In this article, we answered some frequently asked questions (FAQs) about converting from MBR to GPT. We hope this article has provided you with the information you need to successfully convert from MBR to GPT.