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 all of the following are true:

  • The virtual machine resided on a Hyper-V Server 2008 when the virtual machine was backed up.

  • At the time of backup, the virtual machine was not in the Off state.

  • The virtual machine is restored to a Hyper-V Server 2008 R2.

  A Hyper-V message states

  An error occurred while attempting to start the selected virtual
  machine(s). <virtual machine name> could not initialize.
  Saved state file version is incompatible.

  In this case, you must delete the virtual machine's saved state file after the restore and then start the virtual machine. In the Hyper-V Manager interface, right-click on the restored virtual machine and select "Delete Saved State."

• After a redirected restore of the virtual machine on Windows 2008 SP2 and Windows 2008 R2, the virtual machine unexpectedly enters the Saved state. It also fails to start. If the virtual machine was backed up in the Online state, the expected state after restore is Off. But due to a Hyper-V error, the virtual machine incorrectly enters the Saved state.

  During the restore, the Hyper-V-VMMS writes the event ID 12340. The following is a sample message:

  'Saved State' cannot read key '/configuration/_ba8735ef-e3a9-
  4f1b-badd-dbf3a5909915_/VideoMonitor/State' from the repository.
  Error: %%2147778581'(7864368). (Virtual machine ID 
  0AD7DFCC-BDC0-4218-B6DF-7A3BC0A734BF)
  

  In the Hyper-V Manager, you must delete the virtual machine's saved state after the restore and then start the virtual machine.

• 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.