C# Hide Process

private const int SW_HIDE = 0;
private const int SW_SHOW = 5;

[DllImport("User32")]
private static extern int ShowWindow(int hwnd, int nCmdShow);
 //WORKING
private void button1_Click(object sender, EventArgs e)
{
	int hWnd;
	Process[] processRunning = Process.GetProcesses();
	foreach (Process pr in processRunning)
	{
		if (pr.ProcessName == "notepad")
		{
			hWnd = pr.MainWindowHandle.ToInt32();
			ShowWindow(hWnd, SW_HIDE);
		}
	}
}

//NOT WORKING
private void button2_Click(object sender, EventArgs e)
{
	int hWnd;
	Process[] processRunning = Process.GetProcesses();
	foreach (Process pr in processRunning)
	{
		if (pr.ProcessName == "notepad")
		{
			hWnd = pr.MainWindowHandle.ToInt32();
			ShowWindow(hWnd, SW_SHOW);
		}
	}
}

HIDE = 0,
SHOWNORMAL = 1,
SHOWMINIMIZED = 2,
MAXIMIZE = 3,
SHOWMAXIMIZED = 3,
SHOWNOACTIVATE = 4,
SHOW = 5,
MINIMIZE = 6,
SHOWMINNOACTIVE = 7,
SHOWNA = 8,
RESTORE = 9,
SHOWDEFAULT = 10,
FORCEMINIMIZE = 11