Option Explicit

Private Sub Form_Load()
  Dim a As Integer

  For a = 0 To Screen.FontCount - 1
    List1.AddItem Screen.Fonts(a)
  Next a
End Sub

Private Sub List1_Click()
  Label1.FontName = List1.List(List1.ListIndex)

  If IsProportionalFont() = True Then
    Label2.ForeColor = &H8000&
    Label2.Caption = "Ich bin eine Proportional-Schrift, " & _
       "da meine Schrift Zeichen unterschiedliche Breiten haben."
  Else
    Label2.ForeColor = &HC0&
    Label2.Caption = "Ich bin keine Proportional-Schrift, " & _
       "da alle meine Zeichen die gleiche Breite haben."
  End If
End Sub

Private Function IsProportionalFont() As Boolean
  Dim lblWidth(2) As Integer

  Picture1.FontName = Label1.FontName
  lblWidth(0) = Picture1.TextWidth("W")
  lblWidth(1) = Picture1.TextWidth("i")

  If lblWidth(0) <> lblWidth(1) Then
    IsProportionalFont = True
  Else
    IsProportionalFont = False
  End If
End Function