Hyper-V Change UEFI to BIOS | Hyper-V generation 2 to 1

If you want to migrate your Hyper-V virtual machine to Microsoft Azure, you may need to convert your generation 2 VM to generation 1. Is there any way for Hyper-V change UEFI to BIOS? I will introduce how in this article.


By Crystal / Updated on July 6, 2022

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Case: Is there any way for Hyper-V change UEFI to BIOS?


Is it possible to BIOS boot instead of UEFI on Hyper-V Gen 2 type guest? Is there any way for Hyper-V change UEFI to BIOS?

- Question from community.spiceworks.com

Creating virtual machines in the type-1 hypervisor Hyper-V often requires attention to compatibility issues. For example, starting from Windows Server 2012 R2, you can create Hyper-V VMs of generation 2, which differs from generation 1 in firmware and boot technology. Generation 2 VM uses UEFI boot, while generation 1 VM can only boot by legacy BIOS.

Check Hyper-V VM generation via Hyper-V Manager

If you want to manually migrate your Hyper-V virtual machine to Microsoft Azure, or downgrade your Hyper-V to 2008 R2, you may want to convert your generation 2 VM to generation 1, which also means Hyper-V disable UEFI, is there any way for Hyper-V change UEFI to BIOS?

How can Hyper-V change UEFI to BIOS

When creating a Hyper-V virtual machine, you will see a warning “Once a virtual machine has been created, you cannot change its generation”.

To convert a generation 2 VM to generation 1, the key problem you need to solve is exactly Hyper-V change UEFI to BIOS, more specifically the change of GPT to MBR. And then you also must solve the change of SCSI to IDE that will accompany this. Compared to this process, creating a new generation 1 VM and migrate data to it is much easier.

Once a virtual machine has been created, you cannot change its generation.

File-based backup is an effective way to avoid the manual change of UEFI to BIOS. By installing the backup agent on your virtual machine, you can backup and restore your virtual machine as it is a physical machine.

Here I recommend you a professional file-based backup software AOMEI Centralized Backupper. It centralized the features of File, System, Disk, Partition, and SQL Server Backup. In the next part, I will show you how to perform file-based backup via AOMEI Centralized Backupper. You can click the following button to start a free trial.

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How to create a new generation 1 Hyper-V VM

1. Launch Hyper-V Manager, click Action > New > Virtual Machine… to open the wizard. Click Next to continue.

Create new virtual machine on Hyper-V Manager

2. Provide a Name for the new VM. And by checking Store the virtual machine in a different location option you can change the default storage. Click Next.

Specify name and location for new Hyper-V VM

3. Specify the generation of the new virtual machine as Generation 1.

And then click Next and follow the rest steps to create the new generation 1 Hyper-V VM.

Hyper-V specify generation 1

How to convert Hyper-V generation 2 VM to generation 1

1. Launch AOMEI Centralized Backupper, and navigate to Computers > Uncontrolled Computers. Check the target virtual machines (with static IP) from the Computers list, and click Request Control.

Note: a request window will pop up on these windows, once authorized you can backup whenever you like without do this step later.

Request Control

2. Navigate to Tasks > New Task > Disk Backup.

Create a Disk Backup task

3. There are 3 steps to follow.

Firstly, click + Add Computers to specify a source physical/virtual machine, click OK to confirm.

Tip: You can also change the Task Name by moving the cursor over the task name and click on it.

Add Computers

4. Then you need to specify the source disk you want to backup.

Select source data

In addition, click on the inverted arrow sign you can select to backup All disks, Disks containing system partitions, Disks containing partitions with specified drive letters, or Disks containing partitions with matching labels.

Select data based on backup rules

5. Specify a Share or NAS device to store the backup. And then you can click Start Backup.

Add share or NAS device storage

6. The created task will be listed separately in Tasks.

Click Advanced > Restore on the right top of the task, select to Restore to another computer. And specify the newly created generation 1 Hyper-V VM you want to restore to.

Restore to another computer

7. You can also Edit Disk, or Align partition to optimize for SSD in this step. Then you can click Start Restore to restore everything you backed up to the new generation 1 Hyper-V VM.

Restore summary

Note: You cannot access Hyper-V BIOS boot menu via Hyper-V GUI. However, BIOS features can be set in the VM configuration or using a PowerShell script.


While Hyper-V generation 2 VM uses UEFI to boot, generation 1 VM is boot by legacy BIOS. Therefore, if you want to convert Hyper-V generation 2 VM to generation 1, I introduced a workaround way, file-based backup, for Hyper-V change UEFI to BIOS in this article.

In file-based backup way, you cannot just convert generation 1 to generation 2, but also migrate data from physical to virtual machine. AOMEI Centralized Backupper is a effective and convenient software to do this.

Crystal · Editor
Crystal is an editor from AOMEI Technology. She mainly writes articles about virtual machine. She is a positive young lady likes to share articles with peolpe. Off work she loves travelling and cooking which is wonderful for life.