Const connString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data" & _
          "Source={PFAD ZUR ACCESS DATENBANK};"
        Dim cn As New OleDb.OleDbConnection(connString) 'Den ConnectString 
        ' musst du noch anpassen
        Dim passWd As String
        Dim userName As String = "Müller"
        Dim cmd As New OleDb.OleDbCommand("SELECT Password FROM Users WHERE" & _
          "UserName = '" + userName + "'", cn)
        Try
            cn.Open()
            passWd = CType(cmd.ExecuteScalar(), String)
            MessageBox.Show("Password: " + passWd)
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        Finally
            cn.Close()
        End Try