how to connect ms access to C#. i dont know basic steps also.. i need complete details

Use MS Access connection string
http://www.connectionstrings.com/access[^]

or you can create it from visual studio automatically
connection-string-from-visual-studio

Basic steps for database connectivity
MSDN

using System.Data.OleDb;

OleDbConnection con = new OleDbConnection();
            con.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\myFolder\myAccess2007file.accdb;
Persist Security Info=False;";
            con.Open();
            string query = "select * from clienttable";
            OleDbCommand cmd = new OleDbCommand(query, con);
            OleDbDataReader dr = cmd.ExecuteReader();
            DataTable dt = new DataTable();
            dt.Load(dr);
            dataGridView1.DataSource = dt;
            dataGridView1.Show();
            con.Close();

You can amend the above code as per your requirements. We have used OLDB method to get the data from data base to your gridview.

Let me know if you face any problems.