Now if you were using IIS it may be different

/me ducks. I know...I know. ;-)

If you use Integrated Authentication on IIS the user revealed by CGI::remote_user(); would be the OS username. Here is the code:

#!c:\perl\bin\perl.exe -w

use CGI;
my $username = CGI::remote_user();
print "Content-type: text/html\n\n";
print "<h3>Hello $username</h3>";
[download]

And here is the reply

Hello viper\blm

--blm--