Visual Basic.NET - DATAGRIDVIEW

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim cnn As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\PEPE\Desktop\centrosNavarra_correcciones.accdb")

        ' CREADA CONEXION CNN

        ' Dim da As New OleDbDataAdapter("select Código_centro, count(Código_Centro) from Hoja1  group by Código_Centro having(count(Código_Centro) >1) ", cnn)

        '  Dim da As New OleDbDataAdapter("select Código_centro from Hoja1", cnn)

        Dim da As New OleDbDataAdapter("select * from Hoja1", cnn)

        'CREADO ADAPTER DA, RECUPERA DATOS DEL SELECT DE LA CONEXION CNN

        ' EN CASO DE NO FUNCIONAR ESTE SELECT UTILIZAR EL SIMPLE CON EL FILTRO WHERE

        Dim ds As New DataSet

        da.Fill(ds)

        DataGridView1.DataSource = ds.Tables(0)

        Dim buscar As Integer = 19500101

        Dim numero As Integer = 1

        For Each fila As DataGridViewRow In DataGridView1.Rows

            numero += 1

            If fila.Cells("F-EFECT").Value > buscar Then

                fila.Selected = True

            End If

        Next

    End Sub

End Class

If fila.Cells("F-EFECT").Value > buscar Then

     datagridview1.rows.remove(fila)

End If