C#

/// <summary>
/// Converts an image file (e.g. 32*32 pixel JPEG) to an icon file
/// </summary>
/// <param name="filename"></param>
public void ImageToIcon(string filename) {
    Bitmap bm=new Bitmap(filename);
    Icon icon=Icon.FromHandle(bm.GetHicon());
    filename=Path.ChangeExtension(filename, ".ico");
    Stream stream=new FileStream(filename, FileMode.Create);
    icon.Save(stream);
}

ImageToIcon( "c:\\icon.bmp" );

// The following method demonstrates overriding the
// caching policy for a request.
public static WebResponse GetResponseNoCache(Uri uri)
{
    // Set a default policy level for the "http:" and "https" schemes.
    HttpRequestCachePolicy policy = new HttpRequestCachePolicy(HttpRequestCacheLevel.Default);
    HttpWebRequest.DefaultCachePolicy = policy;
    // Create the request.
    WebRequest request = WebRequest.Create(uri);
    // Define a cache policy for this request only. 
    HttpRequestCachePolicy noCachePolicy = new HttpRequestCachePolicy(HttpRequestCacheLevel.NoCacheNoStore);
    request.CachePolicy = noCachePolicy;
    WebResponse response = request.GetResponse();
    Console.WriteLine("IsFromCache? {0}", response.IsFromCache);            
    return response;
}