provider: 命名管道提供程序, error: 40 - 无法打开到 SQL Server 的连接，，，求细节，求解答！
在建立与服务器的连接时出错。在连接到 SQL Server 2005 时，在默认的设置下 SQL Server 不允许进行远程连接可能会导致此失败。 (provider: 命名管道提供程序, error: 40 - 无法打开到 SQL Server 的连接) 
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。 

异常详细信息: System.Data.SqlClient.SqlException: 在建立与服务器的连接时出错。在连接到 SQL Server 2005 时，在默认的设置下 SQL Server 不允许进行远程连接可能会导致此失败。 (provider: 命名管道提供程序, error: 40 - 无法打开到 SQL Server 的连接)

源错误: 


行 28: 
行 29: SqlConnection conn = new SqlConnection(connStr);
行 30: conn.Open();
行 31: String sql = "select * from manager where userName = @UserName and password = @Password";
行 32: SqlCommand cmd = conn.CreateCommand();
 

源文件: d:\WebWorkSpace\WebSite2\Login.aspx.cs 行: 30 

堆栈跟踪: 


[SqlException (0x80131904): 在建立与服务器的连接时出错。在连接到 SQL Server 2005 时，在默认的设置下 SQL Server 不允许进行远程连接可能会导致此失败。 (provider: 命名管道提供程序, error: 40 - 无法打开到 SQL Server 的连接)]
  System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +821651
  System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +186
  System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, SqlConnection owningObject) +759074
  System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject) +114
  System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart) +421
  System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) +181
  System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) +173
  System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) +357
  System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) +30
  System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) +424
  System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) +66
  System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) +494
  System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +82
  System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +105
  System.Data.SqlClient.SqlConnection.Open() +111
  Login.btnSubmit_Click(Object sender, EventArgs e) in d:\WebWorkSpace\WebSite2\Login.aspx.cs:30
  System.Web.UI.WebControls.Button.OnClick(EventArgs e) +105
  System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +107
  System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +7
  System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +11
  System.Web.UI.Page.Ra