How can i make my Help file(CHM) to be installed in the Folder where the user install my application

To include file follow the process as Muralidharan mentioned and to get from the specified location use the following code

private void Form1_HelpRequested(object sender, HelpEventArgs hlpevent)
        {
            string dirpath = string.Empty;
            string filename = "YourFIleName.chm";
            dirpath = System.Environment.CurrentDirectory; //Get the installed direcotry
            string[] files = new string[100];
            do
            {
                if (dirpath == string.Empty || dirpath == Directory.GetDirectoryRoot(dirpath))
                {
                    MessageBox.Show("no helpfile found");
                    break;
                }
                else
                {
                    files = Directory.GetDirectories(dirpath, "ACH"); // If you placed the file in separate folder you can use this

                    if (files.Length > 0)
                    {
                        //MessageBox.Show(files[0]);
                        string strHlp = string.Empty;
                        strHlp = files[0] + "\\ACHWINAPP.chm";
                        Help.ShowHelp(this, strHlp);
                        break;
                    }
                    else
                    {
                        dirpath = Directory.GetParent(dirpath).ToString();
                    }
                }
            } while (true);

        }