Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles _
      Timer1.Tick
 
 
        'Buttonfarbe ändern wenn Prozess läuft/nicht läuft
 
        Dim p As Process
 
        Try
            p = Process.GetProcessById(TextBox2.Text)
        Catch
            Button3.BackColor = Color.Red
        End Try 
 
        If Not IsNothing(p) Then
            Button3.BackColor = Color.LightGreen
        End If
 
 
    End Sub