Convert an existing custom device image to a generation 2 virtual machine

To support Windows 11, your custom device images must be based on generation 2 (Gen2) virtual machines (VMs). If you already have custom device images based on generation 1 (Gen1) virtual machines, you can convert those custom device images by following the steps below. After you've completed these steps, all future Cloud PCs provisioned from the converted device image will be based on Gen2 virtual machines.

Windows 365 won't prevent you from provisioning new Cloud PCs from existing custom images based on Gen1 VMs. However, when you want to add new custom images, Windows 365 will only accept Gen2-based images. Gen 2 VMs are required to support Windows 11.

There are four main steps to this process:

  1. Create a new virtual machine
  2. Convert the Master Boot Record to the GUID partition
  3. Convert the disk to a fixed size and VHD format
  4. Upload the converted virtual machine to Azure

Create a new virtual machine

  1. Make sure that Hyper-V is installed on your management PC. For information on how to install Hyper-V, see Install Hyper-V on Windows 10.
  2. Download your existing custom image virtual hard drive (VHD) file from the Azure storage blob URL to your PC where you have Hyper-V available. The VHD file is the exact size of the OS disk, which can be a large file size. Make sure to use a fast, stable internet connection to download the VHD file, and prepare for long download times. For information on how to download a managed disk, see Download a VHD from Azure. You can also download the VHD by using Azure Storage Explorer directly, both as managed disk or storage blob VHDs.
  3. Switch to your local PC and open Hyper-V Manager.
  4. Under Actions, select New > Virtual Machine. Screenshot of Hyper-V create vm
  5. On the Before You Begin page, select Next.
  6. On the Specify Name and Location page, type a friendly name, like CustomFinanceImageg2, and then select Next. Screenshot of Hyper-V specify name
  7. On the Specify Generation page, select Generation 1 (not Generation 2). Gen2 is needed here to mount the disk and change the partition model to GUID Partition Table (GPT). Select Next. Screenshot of Specify Generation page Hyper-V only supports Gen 2 images in VHDX and Gen 1 images in VHD. Azure only supports Gen 2 images in VHD. Therefore, we're creating a Gen 1 VHD image here in order to convert it to a Gen 2 VHD image.
  8. On the Assign Memory page, set Startup memory to at least 1024 MB, preferably 4096 MB. Select Next. Screenshot of Hyper-V assign memory
  9. On the Configure Networking page, select Default Switch > Next.
  10. On the Connect Virtual Hard Disk page, select Use an existing virtual hard disk. Screenshot of connect virtual hard disk page
  11. For Location, select Browse and select the VHD that you downloaded earlier.
  12. Select Next and on the Summary page select Finish.

Convert the Master Boot Record to the GUID partition

  1. Create a WinPE media ISO. For instructions on how to create an ISO, see Create bootable WinPE media. Alternatively, boot from a Windows 11 ISO and press Shift + F10 to display a CMD prompt.
  2. In Hyper-V Manager, under Virtual Machines, select the new VM, and then under Actions select Settings.
  3. In the left navigation pane, under IDE Controller 1, select DVD Drive.
  4. Under DVD Drive, under Controller, select IDE Controller 1.
  5. Select Image file and browse to the new ISO file you created.
  6. Select OK.
  7. Under Actions, select Start.
  8. Wait for the wpeinit command prompt to open.
  9. To convert the Master Boot Record (MBR) to the GUID Partition Table (GPT) partition, run the following two commands in the wpeinit window. The GPT is the new standard for gen2 based VMs.
    1. To determine the correct disk for conversion and validate it, run mbr2gpt /validate /disk:0.
    2. To convert the disk to the GUID Partition Table (GPT), run mbr2gpt /convert /disk:0 For more information on MBR2GPT, see the MBR2GPT.exe documentation.
  10. After the commands run successfully, move on to the next step.

Convert the disk to a fixed size and VHD format

  1. Shut down the virtual machine.
  2. In Hyper-V Manager, select the new virtual machine > Edit disk (under Actions).
  3. On the Before You Begin page, select Next.
  4. On the Locate Disk page, Browse to the location of the converted disk > Next.
  5. On the Choose Action page, select Compact > Finish. Screenshot of choose compact action
  6. After the process completes, select the new virtual machine again > Edit disk.
  7. On the Before You Begin page, select Next.
  8. On the Locate Disk page, Browse to the location of the converted disk > Next.
  9. On the Choose Action page, select Convert > Next. Screenshot of choose convert action
  10. On the Choose Disk Format page, select VHD > Next. Screenshot of choose VHD disk format
  11. On the Choose Disk Type page, select Fixed size > Next. Screenshot of choose fixed disk type
  12. On the Configure Disk page, Browse to a new location for the disk to be created > Next. Screenshot of saving the disk
  13. On the Summary page, confirm all of the details are correct and select Finish.
  14. After the process completes, dismount the WinPE ISO by following these steps:
    1. In Hyper-V Manager, under Virtual Machines, select the new VM, and then under Actions select Settings.
    2. In the left navigation pane, select IDE Controller 1.
    3. Under DVD Drive, under Controller, select IDE Controller 1.
    4. Select OK.

Upload the converted VHD to Azure

  1. Upload the converted VHD back to Azure. You can use Azure Storage Explorer. For other upload options, see Upload a generalized Windows VHD and use it to create new VMs in Azure.

    Note

    Make sure that the VHD remains VHD in fixed size. VHDX as format isn’t supported on Azure.

  2. Go to the Azure portal, open Images > Create.
  3. Fill in the required fields and make sure to select Gen 2 for VM generation.
  4. Select Review + Create.
  5. After the image is created, you can upload it to the Shared Image Gallery. For instructions on how to upload, see Upload the custom image to a shared image gallery.
  6. You can now add the device image to Windows 365. For information on how to upload custom images, see Add a custom device image.

Next steps

Learn about device configuration.