Server 2016: Convert to UEFI Boot without Reinstalling Server

Consider using the Unified Extensible Firmware Interface (UEFI) mode on Windows Server 2016, but have no idea on how to do it? Relax, this post will show you how to convert Legacy to UEFI in Server 2016 without reinstalling the operating system.


By Emily / Updated on May 12, 2023

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User Story

“I installed Windows Server 2016 on an SSD drive and somehow ended up with a Legacy BIOS installation. The motherboard I am using supports UEFI. So, can I convert the SSD to the GPE format that will support the UEFI boot method? I know I can do a fresh reinstall in the correct format but I have spent hours building up Server 2016 and would like to avoid starting over. So, is there any way to convert to UEFI in Server 2016 without reinstalling?”

Advantages of UEFI over Legacy on Server 2016

The UEFI and Legacy BIOS are two different methods to boot up a computer. Legacy BIOS uses the Master Boot Record (MBR) to save information about the hard drive while the UEFI uses the GUID partition table (GPT). Compared with Legacy BIOS, the UEFI is more powerful and offers more advanced features including:

► UEFI boot mode can help your PC start faster because it boots PC in a more standardized way, launching EFI executables rather than running code from a drive’s master boot record.

► The UEFI firmware can boot from hard drive of 2.2 TB or larger because UEFI uses the GPT partitioning scheme instead of MBR.

► UEFI also supports more than 4 primary partitions on a drive thanks to the GPT partition style

► UEFI supports Secure Boot, helping a computer resist attacks and infection from malware. It can check the OS validity and ensure no malware has tempered with the boot process.

Due to those advantages of UEFI boot setting, many users decide to change the traditional Legacy BIOS to advanced UEFI boot method, like the user in the above scenario. But how to convert to UEFI in Server 2016, 2019, 2022, Windows 11, Windows 10, or other operating system without reinstalling OS? Keep reading, please!

How to convert to UEFI in Server 2016 without reinstalling OS?

From the brief introduction of UEFI and Legacy BIOS, we know the UEFI uses the GPT disk, and Legacy uses the MBR. So, before performing the boot mode conversion, it is necessary to convert the MBR disk to GPT format.

To change MBR to GPT, the most common way is to enter the Windows RE environment and launch Command Prompt, with which you can convert an empty system disk to GPT format. Namely, you need to delete the system partition and other existing partitions during the process. Then everything on the disk will be wiped and you have to invest extra time in OS reinstallation. This has upset lots of users.

So, today we will introduce another better way to help change MBR to GPT, and then convert Legacy BIOS to UEFI in Server 2016 without reinstalling. That’s making use of AOMEI Partition Assistant Server. This reliable partition manager allows you to convert disk from MBR to GPT, or GPT to MBR without damaging any partitions on the disk. Moreover, it can convert the system disk directly without using any installation media to enter Win PreOS mode.

PS.: It comes with a demo version for you to have a free trial. Click the button to download it now.

Free Download Win Server and PC
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Before proceeding, we recommend backing up all necessary data in case you lose them because of any unexpected issues like power failure, or operation errors.

Step 1. Install and launch AOMEI Partition Assistant Server. Right-click the system disk and choose "Convert to GPT".

Convert System Disk To Gpt

Step 2. Click "OK" to confirm your operation.

Ok To Gpt System Disk

Step 3. Back to the main interface, click on "Apply" to commit the pending operation.

Apply To Gpt System Disk

After the MBR to GPT conversion is accomplished, now it is time to convert to UEFI boot mode in Server 2016:

1. Restart your Windows Server 2016, continuously press the F2 or other function keys (F1, F3, F10, or F12), the ESC, or Delete key, which differs from PC to PC, to enter the BIOS setting screen. You can check your PC manufacturer support website for more specific details.

2. On the screen, navigate to the "Boot” menu.

3. At the Boot interface, select "UEFI/BIOS Boot Mode", and press Enter.

4. Then the UEFI/BIOS Boot Mode dialog box appears. Now use the Up and Down arrows to select UEFI boot mode, and then press Enter key.


5. Press "F10" to save the changes and exit the screen.

After that, your Windows Server 2016 will boot into the UEFI mode you've set just now.


So, to convert to UEFI in Server 2016 without reinstalling OS, there are two things to do: convert the Server 2016 system disk from MBR to GPT format, and then switch the boot setting from Legacy to UEFI in BIOS settings to boot Server OS. With the help of AOMEI Partition Assistant Server, this conversion can be quite safe and easy. Besides, it also comes with many other amazing functions, like transfering Server to new hard drive, rebuilding MBR, splitting partition, making bootable media, etc. To install such software on unlimited computers, please try the Unlimited Edition.

Emily · Staff Editor
Emily is an English editor of AOMEI Technology; she has a great passion for providing easy solutions for people to tackle with all disk or partition management problems. In addition to writing articles about disk/partition management, she also edits great tutorials on how to back up and restore disk for data security. In her spare time, she loves to learn computer skill to improve herself or stay with her family to enjoy a good day.