'Im Allgemein Bereich
Dim Handle_ As Boolean
'benötigte Ereignisse
Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
        e.Handled = Me.Handle_
End Sub
Private Sub TextBox1_KeyDown(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyDown
        Me.Handle_ = False
        If e.KeyCode = Keys.V AndAlso (e.Control) Then
            Me.Handle_ = True
        End If
End Sub
'Das ContextMenu einer TextBox kannst du wie folgt entfernen:
Me.TextBox1.ContextMenu = New ContextMenu