Windows 10: GPT needed but disk has OEM partition

Trying to upgrade Windows 10 Home from 32-bit to 64-bit.

After booting from the USB flash drive which, following instructions on the MIcrosoft site had the installation media put on it by the Media Creation tool it asks where do you want to install Windows. This shows

Drive 0 Partition 1 System Reserved 500 MB.

Drive 0 unallocated space 1862 Gb

Drive 0 Partition 2 OEM Reserved when I click for details, it implies that what the OEM has put t here should not be removed


It says "Windows cannot be installed to this disk. The selected disk has an MBR Partition Table. On EFT systems Windows can only be installed to GPT disks. "


I have looked at the Windows Answers and that says it is only possible to convert MBR to GPT if there are no partitions.


I am not very experienced in working at this level and the computer shop has shut completely - bankrupted by the COVID lockdowns, so here is no one to help me.


Please, what do I do?


I am lucky to be able to borrow someones laptop to ask for help!

:)

 

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.

 

OS on MBR, other disks GPT

Hi,

Problem

I don't see the Data Disks in the Windows Explorer

History: What I had before the problem occurred (worked fine)

• Disk 0: 450GB / NTFS / 4 Partitions / used as Windows Home Server OS Disk
• Disk 1: 4TB / GPT / Used as Data Disk
• Disk 2: 4TB / GPT / Used as Data Disk
• Disk 3: 4TB / GPT / Used as Data Disk

What I actually have

• Disk 0: 450GB / NTFS / 2 Partitions / used as Windows 10 Pro OS Disk
• Disk 1: 4TB / GPT / Used as Data Disk
• Disk 2: 4TB / GPT / Used as Data Disk
• Disk 3: 4TB / GPT / Used as Data Disk

What I see in the Windows Disk Management

• Disk 0: Basic, Online
  
  System Reserved, 500MB NTFS, Healthy (System, Active, Primary Partition)
  
  (C, 465 GB NTFS, Healthy (Boot, Page File, Crash Dump, Primary Partition)
• Disk 1: Basic, Online
  
  2048 GB, Healthy (GPT Protective Partition)
  
  1678 GB, Unallocated
• Disk 2: Basic, Online
  
  2048 GB, Healthy (GPT Protective Partition)
  
  1678 GB, Unallocated
• Disk 3: Basic, Online
  
  2048 GB, Healthy (GPT Protective Partition)
  
  1678 GB, Unallocated
• Disk 4: Basic, Online
  
  2048 GB, Healthy (GPT Protective Partition)
  
  1678 GB, Unallocated

What I see in the Windows Explorer

• Local Disk (C

What am I doing wrong?

Moved from: Windows / Windows 10 / Devices & drivers

 

Clean install on a OEM formatted GPT disk?


@jimbo45
In addition, There are couple of ways to find out whether it's MBR or GPT:

1. From disk management. Looking at 2nd partition then you can tell it is GPT
2. Or move the mouse pointer to Disk 0, right click->Properties->Volume. It should tell you it is GPT.