VALIDAR TEXTBOX

Cuando uno empieza a rellenar datos a una caja de texto a veces nos vemos en la problemática de buscar la manera de validar los mismos es decir ..! como hago para que mi caja de texto solo admita numeros, letras, caracteres especiales, que admita solo algunas letras, etc

bueno si mas preámbulo los explicare.:

Textbox que admite solo letras

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
If Char.IsLetter(e.KeyChar) Then
e.Handled = False
ElseIf Char.IsControl(e.KeyChar) Then
e.Handled = False
ElseIf Char.IsSeparator(e.KeyChar) Then
e.Handled = False
Else
e.Handled = True
End If
End Sub

Textbox que admite solo números

    Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
        If InStr(1, "0123456789,-" & Chr(8), e.KeyChar) = 0 Then
            e.KeyChar = ""
        End If
    End Sub

Pasar de un textbox a otro al presionar Enter

    Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
        If e.KeyChar = ChrW(Keys.Enter) Then
            e.Handled = True
            SendKeys.Send("{TAB}")
        End If
    End Sub
    Private Sub TextBox2_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox2.KeyPress
        If e.KeyChar = ChrW(Keys.Enter) Then
            e.Handled = True
            SendKeys.Send("{TAB}")
        End If
    End Sub

Borrar los todos los textbox’s de un formulario

 Private Sub Limpiar_Cajas(ByVal f As Form)
 For Each c As Control In f.Controls
 If TypeOf c Is TextBox Then
 c.Text = ""
 End If
 Next
 End Sub

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

para descargar el proyecto :