From the right pane in Hyper-V Manager Console, select the ‘Import Virtual Machine’ option.
Browse to the folder of your backed up VM and ‘Select Folder’
Choose the type of import to perform.
Complete the import
I’ve been noticing that in some cases when you added a new virtual switch manager other than the default ones in Hyper-V, the VM would fail to start with “Hyper-V Manager: failed to change state.”.
My workaround was doing another import but during the connection selection, selecting a connection for each VM.