With database password (mdb file) using Microsoft.ACE.OLEDB.12.0

Connection string

This Microsoft ACE OLEDB 12.0 connection string can be used for connections to Access 97, Access 2000, Access 2002 and Access 2003.

This is the connection string to use when you have an Access 97 - 2003 database protected with a password using the "Set Database Password" function in Access.

Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\myFolder\myAccessFile.mdb;
Jet OLEDB:Database Password

Some reports of problems with password longer than 14 characters. Also that some characters might cause trouble. If you are having problems, try change password to a short one with normal characters.