First off, is this your NT server, or someone else's? Many ISP's that run NT servers will not install Perl for a myriad of misconceptions. If you're trying to find the path to Perl on a NT server that you are hosting web pages on, most likely they have online documentation that either supports Perl and how to setup your scripts, or says "use something else".
However, if this Perl was put on your own machine there, its usually installed in a couple of places. Basically, my best plan of attack would be to click on "Start", "Find", "Files and Folders" and run a search for Perl. As long as you did a "typical" install, it should find it on one of your drives (you may have to search each individually).
Just a note (and I hope I am not being critical, and this may not apply to everyone): if you are running NT (especially NT server 4) at home, and don't know the specifics of how it works, I would generally suggest using Windows 95/98 as a development platform. It runs Perl just as well as NT, and you can still use Apache, or personal Web server. Using NT, for the sheer weight of saying "I use NT" without understanding what NT is built to do, is like saying "I own my own digital broadcast satellite so I can get ESPN and the Home Shopping Network", when all you need is cable TV. Just a thought.
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Fred Hirsch
Web Consultant & Programmer