Dim conn As OleDbConnection = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\DbOggetti.mdb")
    Dim cmd As OleDbCommand
   
    Private Sub btnINSERT_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnINSERT.Click

        Try
            conn.Open()
            cmd = New OleDbCommand("INSERT INTO nome_tabella (Colonna1, Colonna2, Colonna3) VALUES (@Colonna2 , @Colonna3)", conn)

            'Nel caso in cui la Colonna1 sia la chiave primaria autoincrementante
            cmd.Parameters.Add("@Colonna2", OleDbType.Char).Value = Me.TextBox1.Text
            cmd.Parameters.Add("@Colonna3", OleDbType.Integer).Value = Me.TextBox2.Text

            cmd.ExecuteNonQuery()
            conn.Close()

        Catch ex As Exception
            MsgBox(ex.Message)
        End Try

    End Sub

    Private Sub btnDELETE_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDELETE.Click

        Try

            conn.Open()

            cmd = New OleDbCommand("DELETE FROM nome_tabella WHERE id = " + key + "", conn) 'dove key è l'identificativo della riga della tabella o se vuoi il  Me.cmbCOMUNI.SelectedValue 
            cmd.ExecuteNonQuery()
       
            conn.Close()

        Catch ex As Exception
            MsgBox(ex.Message)
        End Try

    End Sub