Documentation

Hyper-V upgrade generation 1 to generation 2

Note:

⦁ Before doing this conversion, the VM must be backed up.

⦁ Microsoft only supports Server 2012 or Windows 8 and higher for Generation 2 VMs on Hyper-V. Microsoft does not support Server 2008 R2 or Windows 7 and older.

 The process itself only takes a few minutes. Microsoft added a useful tool in 2018 that allows you to convert MBR to GPT Windows hard drives on the fly without data loss. Generation 2 VMs require GPT as the Windows system disk.

1. Get a Windows 10 ISO file (minimum Windows 10 1909 is required)
2. Add this ISO to the Generation 1 VM as CD drive in Hyper-V settings for the VM
3. Boot from the Windows 10 ISO file
4. Choose in Windows setup wizard “repair your computer” than choose “Command prompt” and go to X:\Windows\System32.
5. Enter mbr2gpt /validate /disk:0 (assume disk 0 is your Windows system drive).
6. If no error message appear you can enter mbr2gpt /convert /disk:0 (you can power off this VM afterwards).
7. Example output:
   
8. Create now a new empty Generation 2 VM in Hyper-V Manager and choose the existing Windows VHDX file first to add it to the new Generation 2 VM.
9. Save it and add if existing add other data VHDX files to the VM (make all your other settings as before with the original Generation 1 VM).
10. Boot the new VM and verify the network card IP configuration to match with the previous one (Windows will make a new virtual NIC by default).