...
System.Net.WebClient wc = new WebClient();
 wc.OpenReadCompleted += new OpenReadCompletedEventHandler(wc_OpenReadCompleted);
 wc.OpenReadAsync(new Uri(myFileName, UriKind.Relative), "GET");
...

 void wc_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
        {
            if (e.Error == null)
            {
                 Assembly assembly = loadAssembly(e.Result);
                    if (assembly != null)
                    {
                        object[] versionAttributes = assembly.GetCustomAttributes(typeof(AssemblyFileVersionAttribute), false);
                        if (versionAttributes != null && versionAttributes.Length > 0)
                            tbVersionTxt.Text = string.Format(Properties.Resources.ABOUT_VERSION, ((AssemblyFileVersionAttribute)versionAttributes[0]).Version);
                    }
 
            }
        }


 private Assembly loadAssembly(Stream s)
        {
                string className = (myClassName);
                AssemblyPart ap = new AssemblyPart();
                Assembly a = ap.Load(s);
                return a;
        }

void wc_OpenReadCompleted(object sender, System.Net.OpenReadCompletedEventArgs e)
        {
            if (e.Error == null)
            {
                UnZipper unzip = new UnZipper(e.Result);
                foreach (string filename in unzip.GetFileNamesInZip())
                {
                     if (filename == (myFileName)
                    {
                       Assembly assembly = loadAssembly(unzip.GetFileStream(filename));
                       if (assembly != null)
                       {
                           object[] versionAttributes = assembly.GetCustomAttributes(typeof(AssemblyFileVersionAttribute), false);
                           if (versionAttributes != null && versionAttributes.Length > 0)
                               tbVersionTxt.Text = string.Format(Properties.Resources.ABOUT_VERSION, ((AssemblyFileVersionAttribute)versionAttributes[0]).Version);
                       }
                    }
                }