Your Page's encoding char set is "windows-1256" , so you need to read it using that encoding:
private void GetRepliesStats_Load(object sender, EventArgs e)
{
WebBrowser bro = new WebBrowser();
bro.Navigate("http://library.islamweb.net/hadith/RawyDetails.php?RawyID=1");
bro.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(BrowsingCompleted);
}
private void BrowsingCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
WebBrowser browser = sender as WebBrowser;
Stream documentStream = browser.DocumentStream;
StreamReader streamReader = new StreamReader(documentStream, Encoding.GetEncoding("windows-1256"));
documentStream.Position = 0L;
String My_Result = streamReader.ReadToEnd();
}
I Hope this helps.