Imports System.IO
Public Class Form1
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Try
My.Computer.FileSystem.DeleteFile("c:\test.txt")
Catch ex As Exception

End Try

Dim f As New System.IO.StreamWriter("c:\test.txt", True)
f.WriteLine(TextBox1.Text)
f.WriteLine(TextBox2.Text)
f.WriteLine(TextBox3.Text)
f.WriteLine(TextBox4.Text)
f.Close()
f.Dispose()
End Sub
End Class