Estoy tratando de ejecutar la consulta usando C #, obtengo el siguiente problema

No se especificó un proveedor OLE DB en ConnectionString. Un ejemplo sería, 'Proveedor = SQLOLEDB;

mi código

string strConString = System.Configuration.ConfigurationManager.ConnectionStrings["WorkflowConnStr"].ConnectionString.ToString(); 
string sqlstr = "select * from table"        
OleDbConnection myConnection = new OleDbConnection(strConString);
try
     {myConnection.Open();}
catch (Exception err) 
     { System.Diagnostics.Debug.WriteLine(err.Message); }

OleDbCommand myCommand = new OleDbCommand(sqlstr, myConnection);
OleDbDataReader reader = myCommand.ExecuteReader();

web.config

<add name="WorkflowConnStr" connectionString="Data Source=Server;Initial Catalog=DBName;user id=usr;password=password" providerName="System.Data.OleDb.OleDbConnection"/>

cualquier sugerencia ?