Lost Power, Hyper-V unable to see VM after reconnect back to power

 1) Check if hyper-v is still there 

C/ProgramData/MicroSoft/Windows/Hyper-V/Virtual Machines

https://social.technet.microsoft.com/Forums/scriptcenter/en-US/38f7bf66-0a39-4905-90f8-c6900a4fdfd6/hyperv-guest-vms-disappeared-after-orderly-reboot-not-virus-scanning-issue?forum=winserverhyperv

2) Check hyper-v drive is still there

C:\Users\Public\Documents\Hyper-V\Virtual hard disks

https://community.spiceworks.com/topic/1070304-hyper-v-machines-disappears-after-restart-of-host-machine

3) 

    There are two ways

     a) In Hyper-V select Import Virtual machines, then sets the folder to C/ProgramData/MicroSoft/Windows/Hyper-V/Virtual Machines

           In there select restore

      b) Create a new virtual machine and point it to the virtual machine hard disk in  C:\Users\Public\Documents\Hyper-V\Virtual hard disks\<YourVirtualMachienHardDiskByDate>