Windows 10: Convert Windows 10 Boot Drive Partitions from MBR to UEFI

I would like to convert a boot drive partition that has 2 windows 10's installed on them from MBR to UEFI. Is this possible to do without loosing data and reinstalling windows.

:)

 

Convert Windows 10 MBR to GPT (UEFI)?

In reviewing my Windows 10 Pro (64-bit) system I noted that the Secure Boot Status is showing as "unsupported". Investigating further, it appears either the GPT partition for booting using UEFI (is Secure Boot) has become corrupt or my installation was
never installed for Secure Boot. My Windows 10 install is an auto-upgrade from a Windows 8.1 install.

Is there a way to convert the MBR to GPT without doing a fresh install? I do have a USB recovery drive built at a point I believe I had indications Windows was booting from a GPT (UEFI) partition. In fact, the USB recovery drive shows as being a UEFI drive.

Any suggestions will be appreciated!

Thanks!

 

clone MBR HD to bootable GPT partition?

Hi,

1. You cannot convert mbr to gpt without data loss. otherwise, you can follow directions here:

FROM WINDOWS RECOVERY CONSOLE:

To change a master boot record disk into a GUID partition table disk using a command line

• 
  Back up or move the data on the basic master boot record (MBR) disk you want to convert into a GUID partition table (GPT) disk.
  
• 
  Open an elevated command prompt (right-click Command Prompt, and then click Run as Administrator) and type diskpart. If the disk does not contain any partitions or volumes, skip to step 6.
  
• 
  At the DISKPART prompt, type list disk. Make note of the disk number you want to convert.
  
• 
  At the DISKPART prompt, type select disk <disknumber>.
  
• 
  At the DISKPART prompt, type clean.
  

2. I'd suggest converting your vista drive to a virtual machine, load that up on your windows 10 system and use a program like virtualbox to run it.

 

MBR to UEFI conversion

In addition to the good explanation that Greg provided, I would like to add a technical distinction:

The UEFI is akin to firmware while the MBR is a partitioning method. So you would compare the UEFI to the BIOS, and the MBR to the GPT. You wouldn't speak of converting MBR to UEFI.

I said that the UEFI is akin to firmware, because it's not really firmware. The BIOS really is firmware, because it resides on a chip on the motherboard. But the UEFI is programmable software that sits between the computer’s hardware and the operating
system.

The only compelling reason to convert your hard drive from MBR to GPT is if you need to have more than 4 primary partitions on the drive. MBR is limited to 4 primary partitions. And then, since GPT can't be run from the BIOS, you would need to use the UEFI.

The UEFI has many technical improvements over the BIOS, to be sure, but considering the uncertainty inherent in converting old hardware, there isn't really a good reason to attempt converting from BIOS to UEFI other than the satisfaction in pulling off a
complicated maneuver.