Faccio la connectstring in questo modo:
Public ConnString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source= C:\Aziendale\Aziendale.mdb;Persist Security Info=false;"
Public Cn As New OleDb.OleDbConnection(ConnString)
Public dr As OleDb.OleDbDataReader
Public cmd As OleDb.OleDbCommand
Public sql As String