If you are getting an error like the one below in your ASP.Net application when trying to open an Excel or Access file, you may need to reset IIS.

System.Data.OleDb.OleDbException: Unspecified error
at System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection) at System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.OleDb.OleDbConnection.Open() at

To reset IIS:

• Open a command prompt on the box running IIS.
• Issue the command: iisreset

My situation was that I had code that had previously worked, but it just stopped working one day with the error mentioned above.

Hope this helps.