See the question and my original answer on StackOverflow

Another approach is to use the UI Automation technology that's built in Windows. For example, this sample Console app should work. And because it's event-based, it does not need to use timers which can be context-dependent:

public static void Main(string[] args)
    Automation.AddAutomationEventHandler(WindowPattern.WindowOpenedEvent, AutomationElement.RootElement, TreeScope.Children, (sender, e) =>
        var element = sender as AutomationElement;
        if (element.Current.Name == "Параметры быстродействия")
            Console.WriteLine("hwnd:" + element.Current.NativeWindowHandle);

    Console.ReadLine(); // wait ...
    Automation.RemoveAllEventHandlers(); // cleanup

It works fine on my Windows 10 x64 machine. If this doesn't work, make sure your program and SystemPropertiesPerformance.exe run at the same UAC level.