Broadcasting registry changes with C#

How I landed on making GPO settings through the registry active without having to reboot.

class NativeMethods
{
	[DllImport("user32.dll")]
	private static extern IntPtr SendMessageTimeout(
		IntPtr hWnd,
		uint Msg,
		IntPtr wParam,
		UIntPtr lParam,
		uint fuFlags,
		uint uTimeout,
		out UIntPtr lpdwResult
	);

	public static IntPtr SendMessageTimeoutWrapper() 
	{
		IntPtr HWND_BROADCAST = (IntPtr)0xFFFF;
		uint WM_SETTINGCHANGE = 0x001A;
		uint SMTO_NORMAL = 0x0000;
		uint SMTO_NOTIMEOUTIFNOTHUNG = 0x0008;
		uint uTimeout = 2000;
		UIntPtr lpdwResult;

		//
		//	Broadcast changes to the system.
		//
		return SendMessageTimeout(
			HWND_BROADCAST, 
			WM_SETTINGCHANGE, 
			IntPtr.Zero, 
			UIntPtr.Zero, 
			SMTO_NORMAL | SMTO_NOTIMEOUTIFNOTHUNG, 
			uTimeout, 
			out lpdwResult
		);
	}
}