Unable to connect to database
Problem
You receive the following message when attempting to add or update a record in a Microsoft Access database from your application:
Unable to create record. Unable to connect to database. Unspecified Error. Ensure that MDAC 2.8 is installed in the machine.
When a Microsoft Access database file (MDB) is opened with OPEN or OPEN EXCLUSIVE mode in Microsoft Access, the run-time application cannot update the record since the MDB file is in use. This generally occurs with Microsoft Access or another application has your database open at the same time as your web application.
Solution
Close Microsoft Access and try adding or updating the record again.
See
Unspecified Error. Ensure that MDAC 2.6 or higher is installed in the machine ...
http://support.microsoft.com/default.aspx?scid=kb;en-us;825738