程序没有收集目录信息

我正在编写一个程序，用于收集机器信息以排除故障。在对以管理员身份运行的程序进行了一些工作后，我无法使它正确输出%windir%'drivers中的所有文件。我还遇到了当前用户appdata的问题，它抛出了一个UnauthorizedAccessException，不输出任何东西。我想，好吧，我会写一个服务来解决这个问题。在获得基本服务进行测试之后。我仍然没有看到输出。下面是服务的代码:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Threading.Tasks;
namespace SVCTest
{
    public partial class Service1 : ServiceBase
    {
        public Service1()
        {
            InitializeComponent();
        }
        protected override void OnStart(string[] args)
        {
            while (true)
            {
                OutputDirStructureToFile(
                    Environment.GetEnvironmentVariable("userprofile") + "''Desktop''" + Path.GetRandomFileName() + ".txt", 
                    Environment.ExpandEnvironmentVariables("windir") + "''drivers");
                System.Threading.Thread.Sleep(30000);
            }
        }
        protected override void OnStop()
        {
        }
        /// <summary>
        /// Outputs the structure of a directory to a file.
        /// Uses GetFileStructureRecursive.
        /// </summary>
        /// <param name="outputFileName">The file to be outputed to.</param>
        /// <param name="folder">Directory to get the structure from.</param>
        /// <param name="searchPatern">What to search for. EXAMPLE: *.*</param>
        private void OutputDirStructureToFile(string outputFileName, string folder)
        {
            using (var file = new StreamWriter(outputFileName))
            {
                file.Write(GetFileStrucutre(new DirectoryInfo(folder), "*.*"));
            }
        }
        private string GetFileStrucutre(DirectoryInfo dirInfo, string searchPattern)
        {
            StringBuilder sb = new StringBuilder();
            sb.AppendLine();
            sb.AppendLine("Root " + dirInfo.Root);
            sb.AppendLine();
            sb.Append(GetFileStructureRecursive(dirInfo, searchPattern));
            return sb.ToString();
        }
        private string GetFileStructureRecursive(DirectoryInfo dirInfo, string searchPattern)
        {
            StringBuilder sb = new StringBuilder();
            sb.AppendLine("'r'n Directory of " + dirInfo.FullName + "'r'n");
            foreach (var x in dirInfo.GetFileSystemInfos(searchPattern))
            {
                sb.AppendLine(
                    x.LastWriteTime.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture).PadRight(25)
                    + x.Name.PadRight(50)
                    );
            }
            foreach (var dir in dirInfo.GetDirectories())
            {
                sb.Append(GetFileStructureRecursive(dir, searchPattern));
            }
            //try
            //{
            //    foreach (var dir in dirInfo.GetDirectories(searchPattern))
            //    {
            //        sb.AppendLine(
            //            dir.LastWriteTime.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture).PadRight(25)
            //            + String.Empty.PadRight(15)
            //            + dir.Name.PadRight(50)
            //            + dir.Attributes.ToString().PadRight(50)
            //            + dir.LastAccessTime.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture).PadRight(25)
            //            + dir.CreationTime.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture)
            //            );
            //    }
            //}
            //catch (UnauthorizedAccessException) { }
            //try
            //{
            //    foreach (var file in dirInfo.GetFiles(searchPattern))
            //    {
            //        sb.AppendLine(
            //            file.LastWriteTime.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture).PadRight(25)
            //            + file.Length.ToString("N0").PadRight(15)
            //            + file.Name.PadRight(50)
            //            + file.Attributes.ToString().PadRight(50)
            //            + file.LastAccessTime.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture).PadRight(25)
            //            + file.CreationTime.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture)
            //            );
            //    }
            //}
            //catch (UnauthorizedAccessException) { }
            //try
            //{
            //    foreach (var dir in dirInfo.GetDirectories())
            //    {
            //        sb.Append(GetFileStructureRecursive(dir, searchPattern));
            //    }
            //}
            //catch (UnauthorizedAccessException) { }
            return sb.ToString();
        }
    }
}

你会注意到我注释掉了一个块，认为我可能一次访问了太多的信息。以下是我安装并启动服务后得到的结果:

Root C:'
 Directory of C:'Windows'System32'drivers
2011-04-12 01:38:56      en-US                                             
2009-06-10 15:14:29      gm.dls                                            
2009-06-10 15:14:29      gmreadme.txt                                      
2011-04-12 01:38:56      UMDF                                              
2009-07-13 19:19:10      wimmount.sys                                      
 Directory of C:'Windows'System32'drivers'en-US
2011-04-12 01:38:25      bfe.dll.mui                                       
2011-04-12 01:38:22      ndiscap.sys.mui                                   
2011-04-12 01:38:25      pacer.sys.mui                                     
2011-04-12 01:38:27      qwavedrv.sys.mui                                  
2011-04-12 01:38:22      scfilter.sys.mui                                  
2011-04-12 01:38:20      tcpip.sys.mui                                     
 Directory of C:'Windows'System32'drivers'UMDF
2011-04-12 01:38:56      en-US                                             
 Directory of C:'Windows'System32'drivers'UMDF'en-US

里面肯定缺少一些关键的驱动程序。我怎么也弄不明白它为什么不收集信息。没有AV运行，只是更新了Windows 7和VS.我检查了任何奇怪的文件过滤器管理器驱动程序，但我没有看到任何。