The following issues may prevent a restored virtual machine from starting:

• If you restore a virtual machine to a different Hyper-V server, and the original Hyper-V server and the target server do not have the same number of network adapters (NICs), note: You must configure the network adapter(s) for the restored virtual machine on the target server. Otherwise, the attempt to start the restored virtual machine fails and a message similar to the following appears:

  Microsoft Synthetic Ethernet Port (Instance ID {C549AG45-5925-49C0-
  ADD2-218E70A4A1EA}): Failed to power on with Error 'The system 
  cannot find the path specified.' (0x80070003). (Virtual machine 
  5412BD43-DC85-31CB-A688-1B29CE2C57C8)
  

• The restored virtual machine may fail to start if the virtual machine was not in the Off state at the time of backup.

• For the virtual machines that are configured in a volume GUID with a differencing disk in another volume GUID, redirected restores are not supported. Note that redirected restores are supported if the virtual machine's vhd or vhdx file is configured in a drive-letter volume rather than a volume GUID.

  A virtual machine restore to an alternate location may fail in the following case:

  • The virtual machine's vhd or vhdx file is in a GUID-based volume, and

  • A differencing disk for the same vhd or vhdx is in another GUID-based volume.

  In this case, the attempt to restore the virtual machine to an alternate location fails. The cause of the failure is in the Microsoft Hyper-V Writer. The vhd or vhdx files and other configuration files are restored to the correct location, but registration of the virtual machine fails. As a result, Hyper-V is unable to start the restored virtual machine. A Hyper-V writer event log similar to the following may appear:

  Failed to update the path of the parent disk for virtual 
  hard disk 'E:\restore123\Volume{D2CC1448-BCFD-11CE-96DD-
  001EC9EEF3B2}\test1\diff.vhd' for virtual machine 'test': 
  The system cannot find the path specified. (0x80070003). 
  The disk may not work properly. If you cannot start your virtual 
  machine, remove the disk and try again.(Virtual machine ID <id>)
  
  

  After the restore, you must configure a new virtual machine and attach the restored vhd or vhdx files to the new virtual machine. The restored .xml file contains information on the original configuration of the virtual machine.

• When a virtual machine is restored to a different Hyper-V server: The location of a virtual CD or DVD drive may prevent the virtual machine from restarting.

  The problem occurs in the following case:

  • The original virtual machine had a CD ISO image that is attached to a virtual CD or DVD drive.

  • On the Hyper-V server where the virtual machine was restored: The ISO image is not on the same path as on the original Hyper-V host during backup.

    For example: The virtual machine originally had E:\cd1.iso attached to its virtual DVD drive. But E:\cd1.iso does not exist on the target Hyper-V host, or it exists at a different location, such as F:\cd1.iso. In either case, the restored virtual machine does not turn on.