You should load both ID & Name fields. So write query like
string strQry = "SELECT ID_Field, Name_Field FROM TableName";
Load the data in
DataTable
OleDbCommand cmd = new OleDbCommand(strQry, open());
OleDbDataAdapter adapt = new OleDbDataAdapter(cmd);
adapt.Fill(dt);
And bind the data in
Dropdownlist
Dropdownlist1.DataSource = dt;
Dropdownlist1.DataTextField = "Name_Field";
Dropdownlist1.DataValueField = "ID_Field";
Dropdownlist1.DataBind();
Probably you need to start learn C# & ASP.NET immediately to avoid these situations because these're very basic things. I'm suggesting this for your own good.
Here more than couple of ways to learn anything in Internet.
Education Needed[
^]