Public Function GetSystemFile(ByVal FileName As String, Optional ByVal _
  extension As String = ".exe", Optional ByVal DefaultFullPath As String = "") _
  As String
	Dim ext As String = extension
	If ext <> "" AndAlso Not ext.StartsWith(".") Then 
		ext = "." & ext
	End If
	If FileName.EndsWith(ext) Then 
		ext = ""
	End If
 
	Dim pathString as String = Environment.GetEnvironmentVariable("path")
 
	For Each p as string in pathString.Split(";")
		Try
			Dim CombinedName as string = System.IO.Path.Combine( p, FileName )
			if System.IO.File.Exists( CombinedName ) Then
				return CombinedName
			End If
 
			if NOT string.IsNullOrEmpty( ext ) Then
				 CombinedName = System.IO.Path.ChangeExtension( CombinedName, ext )
				if System.IO.File.Exists( CombinedName ) Then
					return CombinedName
				End If
			End If
		Catch ex As Exception
			MessageBox.Show("Fehler beim auslesen des" & _
			  "Verzeichnisses." & vbCrLf & vbCrLf & "Meldung: " & _
			  vbCrLf & ex.Message, "Fehler...!", _
			  MessageBoxButtons.OK, MessageBoxIcon.Warning)
		End Try
	Next  
	Return DefaultFullPath
End Function