Developing windows application and getting this error "could not save; currently locked by another user. "

"Could not save; currently locked by another user. "

using (OleDbConnection con = new OleDbConnection(ConfigurationManager.AppSettings["connection"]))
                   {
                       con.Open();
                       OleDbCommand cmd = new OleDbCommand("UPDATE REPORTLkgUkg set StudentPhoto=?   where RegID=? and Standard=? ", con);

                       MemoryStream ms = new MemoryStream();
                       pictureBox1.Image.Save(ms, ImageFormat.Jpeg);
                       byte[] photo_aray = new byte[ms.Length];
                       ms.Position = 0;
                       ms.Read(photo_aray, 0, photo_aray.Length);


                       cmd.Parameters.Add(new OleDbParameter("@StudentPhoto", (Object)photo_aray));

                       cmd.Parameters.Add(new OleDbParameter("@RegID", txtRegId.Text));
                       cmd.Parameters.Add(new OleDbParameter("@Standard", cmbStd.Text));
                       cmd.ExecuteReader();

                       cmd.ExecuteNonQuery();
                       con.Close();

                   }