In previous versions of Windows, you were forced to reinstall the entire operating system if you wanted to convert Legacy BIOS or Master Boot Record (MBR) to UEFI or GUID Partition Table (GPT). However, in Windows 10 Microsoft, a new and simple tool called MBR2GPT was introduced. It lets you convert from Legacy BIOS to UEFI with just two commands.
Here is how you can covert from Legacy BIOS to UEFI in Windows 10.
Why Convert Legacy to UEFI?
You probably have some inkling why you’d want to change from the Legacy BIOS to UEFI, but just to confirm, here’s what you need to know. Both BIOS and UEFI perform the same function on your PC – namely under-the-hood software integrated into your motherboard chip that lets you control various important low-level things.
Your BIOS/UEFI lets you control things like boot order, connected hardware, fan speeds, the physical lights on your computer and system time. Modern motherboards even let you undervolt and overclock your CPU! It’s powerful stuff.
UEFI is basically the new BIOS, performing the same job but better. With UEFI, you get faster boot times (ostensibly), higher drive capacities, better update methods and driver support, and a 64-bit mode (where BIOS is only 16-bit).
In other words, switching to UEFI is a bit of an upgrade and worth doing. Note that even modern computers tend to still call the motherboard software the BIOS, even if it’s technically UEFI.
Things You Need to Know Beforehand
Though converting Legacy BIOS to UEFI in Windows 10 is easy, there are a few things you should know and do before proceeding.
1. There will be no data loss while converting Legacy BIOS to UEFI. However, as a precaution, please back up your system.
2. You should be using Windows 10 v1703 or higher. If you are not sure, press Win + R, type winver and press Enter. On the second line, you should see “version 1703” or higher.
3. The disk you are trying to convert should not have more than three partitions. If you have more than three partitions on the Windows 10 installation drive, either merge or delete excess partitions.
4. If you are using BitLocker to encrypt your system, decrypt the drive and disable BitLocker protection before starting the conversion process. With BitLocker protection turned on, Windows 10 cannot convert your drive from Legacy BIOS to UEFI.
5. After converting, you may have to change your motherboard firmware settings from Legacy BIOS to UEFI. Depending on your motherboard manufacturer, the procedure to switch from one to the other will be different. Have your motherboard manual handy to make things easier for you.
If you want to know more, we have a full guide on the differences between UEFI and BIOS for you to check out.
Check Whether You Are Using Legacy BIOS
The last thing you need to check is whether you are using Legacy BIOS. After all, there is no use converting if you are already on UEFI.
To find out, search for “Create and format hard disk partitions” in the Start menu and press Enter to open the built-in Disk Management tool. Now, right-click on the Windows installation disk and select “Properties.”
In the properties Window, go to the “Volumes” tab. Here, if you see “Master Boot Record (MBR)” next to “Partition style,” you are on Legacy BIOS. If, on the other hand, it says “GUID Partition Table (GPT)” like in the image below, then you’re already on UEFI and don’t need to do anything more!
Convert Legacy BIOS to UEFI
Once you’ve confirmed you are on Legacy BIOS and have backed up your system, you can convert Legacy BIOS to UEFI.
1. To convert, you need to access Command Prompt from Windows’s advanced startup. For that, press Win + X, go to “Shut down or sign out,” and click on the “Restart” button while holding the Shift key.
2. The above action will reboot your system to the Advanced Startup screen. Here, go to “Troubleshoot -> Advanced Options” and select the option “Command Prompt.”
3. Validate the disk you are trying to convert. Type the below command and press Enter.
mbr2gpt /validateIf you see the “Validation completed successfully” message, then you can proceed to the next step. If you see any errors, your disk or system may not meet the conversion requirements.
If you have problems validating at this point, then enter the following command:
mbr2gpt /validate /allowFullOS
4. After validating the disk, execute the below command:
mbr2gpt /convertAs soon as you execute, Windows 10 will start the conversion process, i.e., add all the required UEFI boot files and GPT components, then update the Boot Configuration Data.
5. Restart your system, launch your motherboard firmware settings screen and change it from Legacy BIOS to UEFI. The procedure to change from Legacy BIOS to UEFI depends on your motherboard manufacturer. Consult the manual for the exact steps.
6. After booting into Windows 10, you can verify whether or not you are converted. Just like before, open the disk properties window from the Disk Management tool and go to the “Volumes” tab. Here, you should see “GUID Partition Table (GPT)” next to “Partition style.”
Want to do more under-the-hood tweaking in Windows 10? See how to set up port forwarding on the OS. Or for something more tangible, how about learning to make and receive calls on Windows 10 using your Android phone?
