C#

public event ProgressChangeHandler ProgressChanged;

public void GetPC(...)
{
   cr.ProgressChanged += new ProgressChangeHandler(updateProgressBar); //cr is instance of CR5 through iCR interface/factory
   cb.ProgressChanged += new ProgressChangeHandler(updateProgressBar); //cb is C_Comm 
}

public int updateProgressBar(int i)
{
    pb.Value = i;
}

public delegate void ProgressChangeHandler(int progress);
public interface iCR
{
    event ProgressChangeHandler ProgressChanged;
}

public event ProgressChangeHandler ProgressChanged;
private int AttemptWrites()
{
   for(i=0...)
   {
        RaiseProgressChange(i);
   }
}

private void RaiseProgressChange(int progress)
{
    if (ProgressChanged != null)
    {
         ProgressChanged(progress);
    }
}

public delegate void ProgressChangeHandler(int progress);

public class C_Comm{
    public event ProgressChangeHandler ProgressChanged;

    public int Read(byte[] data, int ind)
    {
        for(int i...)
        {
            RaiseProgressChange(i);
        }
    }

    private void RaiseProgressChange(int progress)
    {
        if (ProgressChanged != null)
        {
            ProgressChanged(progress);
        }
    }
}  

public void readRegistryForDX9()
        {
            RegistryKey rk = Registry.LocalMachine;
            RegistryKey sk = rk.OpenSubKey("SOFTWARE\\Wow6432Node\\Microsoft\\DirectX");
            string temp = (string)sk.GetValue("Version");
            if (temp.IndexOf("4.09")<0) MessageBox.Show("Directx 9 Must be installed");
            else MessageBox.Show("Directx 9 already installed");
            return;
        }