The Guardian script has these system requirements:
Web server must support custom Perl CGI.
Some web hosts offer a few system-wide scripts, like a counter or a formmail script, but don't allow you to add your own scripts. Such companies do not support custom Perl CGI.
Web servers like Microsoft IIS support Perl CGI only in the sense that CGI works if the administrators take the extra step of installing Perl and configuring IIS to use it.
Your web server must support Perl CGI and Perl must be installed on the server and the system policy must allow you to use the two together.
Web server must allow CGI scripts to save data to the file system.
In practice, this means that either the file system must be writable for all CGI processes, or there must be some mechanism for changing the permissions of files and folders, usually by FTP/chmod or telnet/chmod or ssh/chmod.
For many Windows web servers, the file system is not writable by default, and there is no way to remotely change file permissions. However, Windows will still work for this script. You may just have to take extra steps, like calling the tech support department to get them to change the file permissions for you. See the install document for more on changing Windows file permissions.
In order to login to the admin page, your version of Perl must support the
cryptfunction. Some older versions of Windows Perl did not support this function under the mistaken belief that supporting it would violate cryptography export laws. All new versions of Windows Perl from ActiveState do support the function.
Finally, your web server must allow a Perl CGI script to handle server errors.
Apache, Microsoft IIS, and Zeus can be configured to allow this. The install document includes specific instructions on how to set up the error handling. In some cases you will need to work with your system administrators to set up the handling. This is particularly true for Microsoft IIS, which doesn't allow error handling to be managed using control files.
"System requirements" http://www.xav.com/scripts/guardian/help/1009.html