Option Explicit
Const LOGDATEI = "\\Server01\service$\Umfrage.txt"
Const SEITE = "http://intranet/survey.php"
Const ForReading = 1, ForWriting = 2, ForAppending = 8
Const TristateUseDefault = -2, TristateTrue = -1, TristateFalse = 0
 
Dim WshNetwork, IExplorer, FSO, f, LogInhalt, ausgefuellt, objEnv, _
  objTextStream, ts
 
Set FSO = CreateObject("Scripting.FileSystemObject")
Set objEnv = CreateObject("WScript.Shell")
Set WshNetwork = WScript.CreateObject("WScript.Network")
Set f = FSO.GetFile(LOGDATEI)
Set ts = f.OpenAsTextStream(ForReading, TristateUseDefault)
 
If FSO.FileExists(LOGDATEI) Then
  Set LogInhalt = FSO.OpenTextFile(LOGDATEI)
  ausgefuellt = False
 
  Do While Not ts.AtEndOfStream
     If UCase(WshNetwork.Username) = UCase(ts.ReadLine) Then
       ausgefuellt = True
       Exit Do
     Else
       ausgefuellt = False
     End If
  Loop
 
  If ausgefuellt = False Then
    Set ts = f.OpenAsTextStream(ForAppending, TristateUseDefault)
 
    If FSO.FileExists(LOGDATEI) Then
      ts.WriteLine (WshNetwork.Username)
    End If
 
    Set IExplorer = CreateObject("InternetExplorer.Application")
    Do While IExplorer.Busy
    Loop
    IExplorer.Visible = True
    IExplorer.Navigate SEITE
    'WindowState = 2 ' vbMaximized
  End If 
Else
  WScript.Echo LOGDATEI & " nicht gefunden!"
End If