This directory contains the proTeXt (http://tug.org/protext) as an ISO image. Normally, you should download the protext distribution from your nearest CTAN mirror (CTAN:systems/windows/protext); it is smaller and simpler to unpack. The only reason to use this is when you need to burn your own physical cd. See the proTeXt web pages for more information. Please consider joining a TeX user group (e.g., http://tug.org/join.html) to support this effort (and get the entire TeX Collection on DVD).