aspnet_regsql - Unable to connect

Jeg har problemer med at connecte til SQL Server 2005 med aspnet_regsql på lokalmaskine.
ASP.NET SQL Server Setup Wizard kommer med følgende dump:

Setup failed.

Exception:
Unable to connect to SQL Server database.

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Details of failure
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System.Web.HttpException: Unable to connect to SQL Server database. ---> System.Data.SqlClient.SqlException: An error has occurred while establishing a connection to the server.  When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)
  at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
  at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
  at System.Data.SqlClient.TdsParser.Connect(Boolean& useFailoverPartner, Boolean& failoverDemandDone, String host, String failoverPartner, String protocol, SqlInternalConnectionTds connHandler, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, SqlConnection owningObject, Boolean aliasLookup)
  at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance)
  at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance)
  at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection)
  at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options)
  at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject)
  at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject)
  at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject)
  at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
  at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
  at System.Data.SqlClient.SqlConnection.Open()
  at System.Web.Management.SqlServices.GetSqlConnection(String server, String user, String password, Boolean trusted, String connectionString)
  --- End of inner exception stack trace ---
  at System.Web.Management.SqlServices.GetSqlConnection(String server, String user, String password, Boolean trusted, String connectionString)
  at System.Web.Management.SqlServices.SetupApplicationServices(String server, String user, String password, Boolean trusted, String connectionString, String database, String dbFileName, SqlFeatures features, Boolean install)
  at System.Web.Management.SqlServices.Install(String database, SqlFeatures features, String connectionString)
  at System.Web.Management.ConfirmPanel.Execute()