Hi, this used to work on Windows 7 64, but doesn't on Windows 10 64: Func _isWorkstationLocked() $hDesktop = DllCall("User32.dll", "int", "OpenDesktop", "str", "Default", "int", 0, "int", 0, "int", 0x100) $ret = DllCall("User32.dll", "int", "SwitchDesktop", "int", $hDesktop[0]) DllCall("User32.dll", "int", "CloseDesktop", "int", $ret[0]) If $ret[0] Then Return SetError(0, 0, 0) Else Return SetError(0, 0, 1)