If you password protected the whole access database, then you need to use
Dim strConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & _
System.Environment.CurrentDirectory & "\data.mdb;Jet OLEDB:Database Password=ehsan"
The error is saying that it is expecting a workgroup information file. If the fix above doesn't work, then look here:
Common data access page deployment Errors[
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