Windows 8.1 Hyper V Virtual Switch Manager - Cannot add New Virtual Switch

I'm trying in vain to add A New Virtual Switch on my Hyper V host machine, but I keep getting the same crash-report regardless of what I'm trying to do.

PS C:\WINDOWS\system32> New-VMSwitch "VM Network" -NetAdapterName "Ethernet" -AllowManagementOS $True
New-VMSwitch : Failed while creating virtual Ethernet switch.
Switch create failed, name = '5C401793-219A-452D-9DFF-8E1F3A791A88', friendly name = '': %%3758096900 (0xE0000204).
At line:1 char:1
+ New-VMSwitch "VM Network" -NetAdapterName "Ethernet" -AllowManagementOS $True
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (Microsoft.HyperV.PowerShell.VMTask:VMTask) [New-VMSwitch], Virtualization
   OperationFailedException
    + FullyQualifiedErrorId : OperationFailed,Microsoft.HyperV.PowerShell.Commands.NewVMSwitchCommand

PS C:\WINDOWS\system32>

I have already done a Remove/Add of HyperV and a Windows Update Search but still the same error. Can it be related to a VPN installation on the hos pc ?

I'm not a master of hardware and networks, just trying to setup a Hyper V virtual machine,

Thomas Elbek