To replace a standard Network Adapter with a Legacy Network Adapter in Hyper-V:

Important

  • Legacy Network Adapter is only supported on Generation 1 VMs.
  • Generation 2 VMs cannot use Legacy Network Adapters.
  • Legacy adapters are mainly used for PXE booting older operating systems that don't have Hyper-V synthetic NIC drivers.

Remove the Existing Network Adapter

  1. Open Hyper-V Manager.
  2. Make sure the VM is powered off.
  3. Right-click the VM and select Settings.
  4. In the left pane, select Network Adapter.
  5. Click Remove.

Add a Legacy Network Adapter

  1. In the VM Settings window, select Add Hardware.
  2. Choose Legacy Network Adapter.
  3. Click Add.
  4. Select the appropriate Virtual Switch from the drop-down list.
  5. Click Apply and OK.

If "Legacy Network Adapter" Is Missing

Check the VM generation:

  1. In Hyper-V Manager, right-click the VM.
  2. Select Settings.
  3. Click Summary (or look in the VM details pane).

Alternatively, run PowerShell:

Get-VM "VMName" | Select-Object Name,Generation
  • Generation 1 → Legacy Network Adapter available.
  • Generation 2 → Legacy Network Adapter not supported.

PowerShell Method

Remove current adapter:

Remove-VMNetworkAdapter -VMName "VMName" -Name "Network Adapter"

Add legacy adapter:

Add-VMNetworkAdapter -VMName "VMName" -IsLegacy $true -SwitchName "vSwitch Name"