ACCESS DENIED to .mdb files

just check your code if there is some problem....or may be due to some connectivity problem.Try this code and then open database again may your problem will be solved.

Public Function Open_db()

Set db = New ADODB.Connection

With db

.Provider = "Microsoft.Jet.OLEDB.4.0"

.Properties("Data Source") = App.Path & "\your.mdb"

.Properties("Jet OLEDB:Database Password") = "yourpassword"

.Open

End With
End Function