I m writing a program that parses the log files of a Windows service. The program works just fine, it can read and parse correctly log files and so on. The problem is, when I try to run it with the service active, it returns a IOError, I guess because the files are "locked" or something like that. Is there a workaround? This is the code I use to read and parse the files:

private void OnTimedEvent(object source, ElapsedEventArgs e)
{
    var t = Task<int>.Factory.StartNew(() => 
        {
            string[] arr = FileManager.getFiles(textBox1.Text);
            string destination = textBox1.Text + "\backup\";
            string filename = "backup.bak";

            if (!Directory.Exists(@destination))
            {
                Directory.CreateDirectory(@destination);
            }

            StreamWriter w = File.AppendText(@destination+backupfile);

            foreach (string s in arr)
            {
                string sLine = "";
                StreamReader objReader = new StreamReader(s);
                while (sLine != null)
                {
                    sLine = objReader.ReadLine();
                    if (!String.IsNullOrEmpty(sLine))
                    {
                        List<string> output = Parser.parse(sLine);
                        StreamWriter hh = File.AppendText(@textBox2.Text + filename);

                        for(int i = 3; i < output.Count; i++)
                        {
                            string str = output[i];

                            if (!String.IsNullOrEmpty(str))
                            {
                                hh.WriteLine(str);
                            }
                        }
                        hh.Close();
                        w.WriteLine(sLine);
                    }
                }
                objReader.Close();
                //File.Delete(s);
            }
            w.Close();
            return 1;
        });
}