Here is your code (assuming your primary key is named
id):
private void button1_Click_1(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection("Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=sales;Data Source=MERITECH-PC");
con.Open();
SqlCommand cmd = new SqlCommand("Select * from new where id=@id", con);
cmd.Parameters.Add("@id", SqlDbType.Int).Value = 1;
SqlDataReader dr = cmd.ExecuteReader();
if (dr.HasRows)
{
dr.Read();
txt1.Text= dr[0].ToString();
txt2.Text = dr[1].ToString();
txt3.Text = dr[2].ToString();
txt4.Text = dr[3].ToString();
txt5.Text = dr[4].ToString();
}
con.Close();
}