Permissions Error Trying To Run SQL 2005 Express

We have a windows forms app (VB.NET) that uses SQL Server 2005 Express in user instance mode. We have installed the app on hundreds of Win2K and WinXP PCs without any problems, but have run into an issue with one customer's site. They are running Win2K SP4 and we have installed the application on a couple of PCs at the customer's site to determine if it is environmental. The error occurs as the program is starting up the user instance of the database:



Error information:

System.InvalidOperationsException: An error occurred creating the form. See Exception.InnerException for details.

The error is: User does not have permission to perform this action, ---> System.Data.SqlClient.SqlException: User does not have permission to perform this action.

at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)

at System.Data.SqlClient.TdsParser.TrhowExceptionAndWarning(TdsParserStateObject stateObj)

at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)

at System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK)

at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, Object providerInfo, 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 option, 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()



This error occurs at the first attempt to write to the database during the program startup. Any ideas?



Shawn