Use the following Script and run
Set obj = CreateObject("WScript.Shell")
sCmnd = "%windir%\SYSTEM32\rundll32.exe user32.dll,LockWorkStation"
obj.Run sCmnd, 0, False
Set obj = CreateObject("WScript.Shell")
sCmnd = "%windir%\SYSTEM32\rundll32.exe user32.dll,LockWorkStation"
obj.Run sCmnd, 0, False