ah Yes ! got it working !!!
The Final Code :
#include <IE.au3>
_IEErrorHandlerRegister()
$vpcApp = ObjCreate ("VirtualServer.Application", "localhost" )
MsgBox (0,"", "Func Call VirtualMachines")
$vmcollection = $vpcApp.VirtualMachines
For $vm in $vmCollection
MsgBox (0,"", "FindVirtualMachine")
$objVM = $vpcApp.FindVirtualMachine($vm.Name)
MsgBox (0,"", "TurnOff")
$objVM.Turnoff ()
MsgBox (0,"", "Unregister")
$vpcApp.UnregisterVirtualMachine($objVM)
Next
The problem was "Localhost" at the objcreate !