Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ComboBox1.Text =dg.Columns(5).Name
        ComboBox1.Width = dg.Columns(5).Width
        ComboBox1.Top = dg.Top
        ComboBox1.Height = dg.Rows(0).Height

        Dim Wdth As Single = 0
        For I = 0 To 4
            Wdth = Wdth + dg.Columns(I).Width
        Next I
 ComboBox1.Left = dg.Left + Wdth + 41.5
        ComboBox1.Top = dg.Top + 20.5
        ComboBox1.Text = dg(5, pos).Value
    End Sub

Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged

        Dim txt

        Dim pos As Integer

        pos = BindingContext(dt).Position

        txt = ComboBox1.SelectedItem

        dt.Rows(pos).Item(5) = txt

    End Sub

    Private Sub dg_CellEnter(sender As Object, e As DataGridViewCellEventArgs) Handles dg.CellEnter

        Dim pos, POS1

        pos = BindingContext(dt).Position : TextBox2.Text = pos

        If pos >= dt.Rows.Count Then GoTo 10

        POS1 = dg.FirstDisplayedScrollingRowIndex

        ComboBox1.Top = 22 * (pos - POS1) + dg.Top + 21

        ComboBox1.Text = dg(5, pos).Value

10:     pos = pos

    End Sub