X-Mouse or Focus-Follow-Mouse on Windows 7

I started using Windows 7 only because my Windows XP machine's harddisk was failing on me. My new machine came with Windows 7 installed. After some tweaking the settings I could not find a way to enable the Focus-Follow-Mouse-Without-Raising-Windows behaviour I was used to. On Windows XP I used Tweak UI to enable this, but that doesnot exist for Windows 7. Turned out the following C# Console Application does the trick!

For more info look at the SystemParametersInfo function documentation at MSDN.

using System.Runtime.InteropServices;

namespace SPI
{
    class Program
    {
        [DllImport("user32", CharSet = CharSet.Auto)]
        public static extern bool SystemParametersInfo(uint uiAction, uint uiParam, bool pvParam, uint fuWinIni);

        /// Determines whether active window tracking (activating the window the mouse is on) is on or off. The pvParam parameter must point
        /// to a BOOL variable that receives TRUE for on, or FALSE for off.
        /// Windows NT, Windows 95:  This value is not supported.
        public const uint SPI_GETACTIVEWINDOWTRACKING = 0x1000;
        /// Sets active window tracking (activating the window the mouse is on) either on or off. Set pvParam to TRUE for on or FALSE for off.
        /// Windows NT, Windows 95:  This value is not supported.
        public const uint SPI_SETACTIVEWINDOWTRACKING = 0x1001;
        /// Determines whether windows activated through active window tracking will be brought to the top. The pvParam parameter must point
        /// to a BOOL variable that receives TRUE for on, or FALSE for off.
        /// Windows NT, Windows 95:  This value is not supported.
        public const uint SPI_GETACTIVEWNDTRKZORDER = 0x100C;
        /// Determines whether or not windows activated through active window tracking should be brought to the top. Set pvParam to TRUE
        /// for on or FALSE for off.
        /// Windows NT, Windows 95:  This value is not supported.
        public const uint SPI_SETACTIVEWNDTRKZORDER = 0x100D;

        static void Main(string[] args)
        {
            // set mouse to x-mouse behaviour, focus on window under mouse without raising the window to top
            bool enable = true;
            bool disable = false;
            SystemParametersInfo(SPI_SETACTIVEWINDOWTRACKING, 0, enable, 0);
            SystemParametersInfo(SPI_SETACTIVEWNDTRKZORDER, 0, disable, 0);
        }
    }
}