Public Class Form1
    Dim zaehler As Integer = 0
    Dim konfigtxt As String = "C:\konfig.txt"
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        DeleteEnter(konfigtxt)
    End Sub
 
    Public Sub DeleteEnter(ByVal textfile As String)
        zaehler = 0
        Dim Lines() As String = IO.File.ReadAllLines(konfigtxt)
 
        For Each line As String In Lines
            zaehler += 1
            If line.Contains(vbCrLf) Then
                MsgBox("true")
                Lines(zaehler - 1) = Lines(zaehler - 1).Replace(vbCrLf, "")
            End If
        Next line
 
        IO.File.WriteAllLines("C:\konfig1.txt", Lines)
        zaehler = 0
    End Sub
End Class