How to convert my hard disk PartitionStyle from GPT back to RAW in Windows 10

RAW is not a Partition type the way MBR or GPT is.

When Windows shows your HDD partition as RAW, it is NOT the Partition style it is talking about. It is the state of the file system installed on that Partition.

And what it really means is that Windows cannot understand what that File System it is - not that is has a recognizable system called RAW.

If you still want to convert your partition to RAW:

• Open the Run window (Win + R)
• type CMD and hit Enter
• type diskpart and hit Enter
• type list disk and hit Enter
• type select disk x, where x is the number of the disk you want to access...might be 0 or 1, then hit Enter
• you should now have the disk you want RAW ready to be cleaned
• WARNING: the following command will erase ALL data from the disk! DO NOT DO THIS IF YOU NEED THE DATA ON THAT PARTITION!
• type clean and hit Enter
• the disk is now RAW.

Example session on Azure VM running Windows 10:

C:\> diskpart

Microsoft DiskPart version 10.0.19041.610

Copyright (C) Microsoft Corporation.
On computer: test-vm

DISKPART> list

Microsoft DiskPart version 10.0.19041.610

DISK        - Display a list of disks. For example, LIST DISK.
PARTITION   - Display a list of partitions on the selected disk.
              For example, LIST PARTITION.
VOLUME      - Display a list of volumes. For example, LIST VOLUME.
VDISK       - Displays a list of virtual disks.

DISKPART> list disk

  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          127 GB  2048 KB
  Disk 1    Online           64 GB      0 B
  Disk 2    Online         1024 GB  1023 GB        *

DISKPART> select disk 2

Disk 2 is now the selected disk.

DISKPART> clean

DiskPart succeeded in cleaning the disk.

DISKPART> list disk

  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          127 GB  2048 KB
  Disk 1    Online           64 GB      0 B
* Disk 2    Online         1024 GB  1024 GB

DISKPART> exit

Leaving DiskPart...

You can verify the partition style by running the following Powershell command:

PS> Get-Disk

Number Friendly Name Serial Number                    HealthStatus         OperationalStatus      Total Size Partition
                                                                                                             Style
------ ------------- -------------                    ------------         -----------------      ---------- ----------
0      Virtual HD                                     Healthy              Online                     127 GB MBR
1      Virtual HD                                     Healthy              Online                      64 GB MBR
2      Msft Virtu...                                  Healthy              Online                       1 TB RAW

Disclaimer: I'm reposting the summary of this thread to preserve the knowledge and make it more discoverable: https://forums.tomshardware.com/threads/how-to-i-convert-my-hard-disk-partitionstyle-from-gpt-to-raw-with-either-cmd-powershell-or-disk-management.1720971/

Credit goes to iprodigyxx, Paperdoc, pegleg1960 and other contributors there.