Сбой кодировки в TextBox

foreach (Match matchess in matches)
{
    textBox1.AppendText(matchess.Value + Environment.NewLine);
    textBox1.AppendText("Содержание : " + Environment.NewLine);
    textBox1.AppendText(matchess.Groups["tegData"].Value + Environment.NewLine); 
    textBox1.AppendText("_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_" + Environment.NewLine);
    textBox1.AppendText(Environment.NewLine);
}

string data = GetHtmlPageText("здесь строка сайта");
 
Encoding srcEncodingFormat = Encoding.GetEncoding("windows-1252");
byte[] originalByteString = srcEncodingFormat.GetBytes(data);
data = Encoding.Default.GetString(originalByteString);
 
string tag = "div";
string pattern = string.Format(@"\<{0}.*?\>(?<tegData>.+?)\<\/{0}\>", tag.Trim());
Regex regex = new Regex(pattern, RegexOptions.ExplicitCapture);
MatchCollection matches = regex.Matches(data);

 public static string GetHtmlPageText(string url)
        {
            WebClient client = new WebClient();
            using (Stream data = client.OpenRead(url))
            {
                using (StreamReader reader = new StreamReader(data))
                {
                    return reader.ReadToEnd();
                }
            }
            
        }

public static string GetHtmlPageText(string url)
{
    using (WebClient client = new WebClient())
    using (Stream data = client.OpenRead(url))
    using (StreamReader reader = new StreamReader(data, Encoding.GetEncoding(1251)))
    {
        return reader.ReadToEnd();
    }
}

public static string GetHtmlPageText(string url)
{
    using (WebClient client = new WebClient())
    {
        client.Encoding = Encoding.GetEncoding(1251);
        return client.DownloadString(url);
    }
}