First, I got the HTTP 400 - Bad Request. So I figure I can just reinstall IIS 5.1 again, so all the configuration will back to default.

Then, an error occur after I tried to run the command.
"Windows can't find sysocmgr/i:c:\windows\inf\sysoc.inf"

I went into windows folder and found that file sitting right there. So I thought I must mess up something in Windows configuration. I reformatted the HD and reinstalled XP again.
Guess what, the problem is still here.
I feel I never going to set up this server. Problems are poping up left and right.

I have been using this command for several times now and never had any problems before. All of the sudden, it stopped working.

Here is the file:
[Components]
iis_common = on
iis_inetmgr = on
iis_www = on
iis_ftp = on
iis_htmla = on

[InternetServer]
PathFTPRoot="x:\InetPub\FTPRoot"
PathWWWRoot="x:\InetPub\wwwroot"

command line:
sysocmgr/i:%windir%\inf\sysoc.inf /u:c:\iis.txt