Run a script for 20minutes

Hi, I have PHP3 and MySQL on Win98 and am trying to run a script that loops through a file making process and it needs about 20 - 30 minutes to run. It generates static HTML files based on content in a database. I've increased Internet Explorer's timeout to allow for this but for some reason only about half the processing is done before everything seems to just stop. Does anyone know of a very basic way of executing a PHP script on a Win98 machine without the need for a browser? Or, another way of running this script that will take some time and create some 22,000 files through the process. Thanks, Martin.