Problem:
Restoring a virtual machine to a Hyper-V cluster fails, stating that the virtual machine already exists, however, Hyper-V Manager does not list the VM.
Cause:
This is usually caused by a partially deleted VM. In case of a clustered Hyper-V there is the virtual machine and an associated cluster role. When the virtual machine is deleted via the Microsoft’s Failover Cluster Manager or SCVMM both the VM And the role are deleted. However, if the virtual machine is deleted via PowerShell or Hyper-V Manager the cluster role may remain.
Solution:
Ensure both the virtual machine and the associated cluster role are deleted, before you re-try the restore.