This method we’ll re-assign the “missing” Symbolic links and give permissions to the Service SID.

Using Mklink, create the Symbolic link under „C:\ProgramData\Microsoft\Windows\Hyper-V\Virtual Machines“

Mklink "C:\ProgramData\Microsoft\Windows\Hyper-V\Virtual Machines\{VM-GUID}.xml" "D:\Virtual Machines\{VM-NAME}\{VM-GUID}.xml"

Now give access permissions to the service SID to this Symbolic link.

icacls "C:\ProgramData\Microsoft\Windows\Hyper-V\Virtual Machines\{VM-GUID}.xml" /grant "NT VIRTUAL MACHINE\{VM-GUID}":(F) /L

Then you need to give access permissions to the Service SID to all files in VM01

icacls D:\Virtual Machines\{VM-NAME}\ /T /grant "NT VIRTUAL MACHINE\VM-GUID}":(F)

Since VM01 has also Snapshots, we need to create the correspondent symbolic link and give the necessary permissions to the files (This process must be done to each snapshot).

mklink "C:\ProgramData\Microsoft\Windows\Hyper-V\Snapshots\324E6E76-77EC-4671-9E25-3D4B5D3133BA.xml" "F:\VM01\Snapshots\VM-GUID}.xml"

Mklink "C:\ProgramData\Microsoft\Windows\Hyper-V\Snapshots\D6EC4773-75A6-49E7-84D2-3B619D1D450C.xml" "F:\VM01\Snapshots\VM-GUID}.xml"

Now, assign the permissions:

Icacls C:\ProgramData\Microsoft\Windows\Hyper-V\Snapshots\324E6E76-77EC-4671-9E25-3D4B5D3133BA.xml /grant "NT VIRTUAL MACHINE\VM-GUID}":(F) /L

Icacls C:\ProgramData\Microsoft\Windows\Hyper-V\Snapshots\D6EC4773-75A6-49E7-84D2-3B619D1D450C.xml /grant "NT VIRTUAL MACHINE\VM-GUID}":(F) /L

Go to the settings of the VM01 and assign the proper Network switch. Start VM01 and you’re DONE!!!! Enjoy.

Zdroj: http://eniackb.blogspot.cz/2009/05/how-to-recover-hyper-v-virtual-machine.html