I had the same problem a few days back. On NT/W2K, the #!line is ignored. It is one of the quirks of activestate perl (using activeperl 5.6.1 build 631).You can do two things : 1. Change the perl you associate with your *.pl or *.cgi files to include a '-T' command line option 2. Create a new extension 'tcgi' or 'tpl' and associate this with "C:/whereverYourPerlExeIs/perl.exe -T". Use this extension with all your scripts which need taint checking. Hope this helps. --Mahesh