C#

private const int SW_SHOWNORMAL    = 1;
private const int SW_SHOWMINIMIZED = 2;
private const int SW_SHOWMAXIMIZED = 3;

<br />
And also dispose the returned processes!<br />

foreach (Process newProcess in newProcesses)<br />
{<br />
    newProcess.Dispose(); //frees the memory and has nothing to do with the started program itselfe!<br />
}

<br />
        private void btnGvim_Click(object sender, EventArgs e)<br />
        {<br />
            Process[] p = Process.GetProcessesByName("gvim");<br />
            int number1 = (int)p[0].MainWindowHandle;<br />
            if (p[0].MainWindowHandle != IntPtr.Zero)<br />
            {<br />
                ShowWindow(number1, SW_SHOWNORMAL);<br />
            }<br />
            p = Process.GetProcessesByName("notepad");<br />
            number1 = (int)p[0].MainWindowHandle;<br />
            if (p[0].MainWindowHandle != IntPtr.Zero)<br />
            {<br />
                ShowWindow(number1, SW_SHOWMINIMIZED);<br />
            }<br />
        }<br />

private void btnGvim_Click(object sender, EventArgs e)
{
    Process[] allProcesses= Process.GetProcessesByName("gvim");
    if(allProcesses.Length>0)
    {
        if (allProcesses[0].MainWindowHandle != IntPtr.Zero)
        {
            ShowWindow(allProcesses[0].MainWindowHandle, SW_SHOWNORMAL);
        }
    }
    DisposeProcesses(allProcesses);

    allProcesses= Process.GetProcessesByName("notepad");
    if(allProcesses.Length>0)
    {
        if (allProcesses[0].MainWindowHandle != IntPtr.Zero)
        {
            ShowWindow(allProcesses[0].MainWindowHandle, SW_SHOWMINIMIZED);
        }
    }
    DisposeProcesses(allProcesses);
}
 
//Help method which disposes all process instances of the passed process array!
public static void DisposeProcesses(Process[] processes)
{
    if(processes!=null)
    {
        if(processes.Length>0)
        {
            foreach(Process p in processes)
            {
                p.Dispose();
            }
        }
    }
}

/// <summary>
/// Gets a Flag if Window is Iconic or not
/// </summary>
/// <param name="hWnd">windowhandle</param>
/// <returns>true or false</returns>
[System.Runtime.InteropServices.DllImport("user32.dll")]
[return: System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.Bool)]
private static extern bool IsIconic(IntPtr hWnd);

string message = "Hello world.";
Console.WriteLine(message);

Console.WriteLine("Hello world.");