Public Class Form1
 
    Private Sub TextBox1_KeyUp(sender As Object, e As KeyEventArgs) Handles _
      TextBox1.KeyUp
        If e.Shift = True And e.KeyCode = 9 Then
            Button1.Focus()
        ElseIf e.KeyCode = 9 Then
            TextBox2.Focus()
        End If
    End Sub
 
    Private Sub TextBox2_KeyUp(sender As Object, e As KeyEventArgs) Handles _
      TextBox2.KeyUp
        If e.Shift = True And e.KeyCode = 9 Then
            TextBox1.Focus()
        ElseIf e.KeyCode = 9 Then
            RadioButton1.Focus()
        End If
    End Sub
 
    Private Sub RadioButton1_KeyUp(sender As Object, e As KeyEventArgs) Handles _
      RadioButton1.KeyUp
        If e.Shift = True And e.KeyCode = 9 Then
            TextBox2.Focus()
        ElseIf e.KeyCode = 9 Then
            RadioButton2.Focus()
        End If
    End Sub
 
    Private Sub RadioButton2_KeyUp(sender As Object, e As KeyEventArgs) Handles _
      RadioButton2.KeyUp
        If e.Shift = True And e.KeyCode = 9 Then
            RadioButton1.Focus()
        ElseIf e.KeyCode = 9 Then
            Button1.Focus()
        End If
    End Sub
 
 
    Private Sub Button1_KeyUp(sender As Object, e As KeyEventArgs) Handles _
      Button1.KeyUp
        If e.Shift = True And e.KeyCode = 9 Then
            RadioButton2.Focus()
        ElseIf e.KeyCode = 9 Then
            TextBox1.Focus()
        End If
    End Sub
 
    Private Sub RadioButton2_PreviewKeyDown(sender As Object, e As _
      PreviewKeyDownEventArgs) Handles RadioButton2.PreviewKeyDown
        If e.Shift = True And e.KeyCode = 9 Then
            RadioButton1.Focus()
        ElseIf e.KeyCode = 9 Then
            Button1.Focus()
        End If
    End Sub
 
    Private Sub RadioButton1_PreviewKeyDown(sender As Object, e As _
      PreviewKeyDownEventArgs) Handles RadioButton1.PreviewKeyDown
        If e.Shift = True And e.KeyCode = 9 Then
            RadioButton2.Focus()
        ElseIf e.KeyCode = 9 Then
            TextBox1.Focus()
        End If
    End Sub
End Class