Are you running PHP as CGI [ this will require a running webserver and some editing to config.sys]
SET PATH=%PATH%;"c:\your\path\to\php"
Hopefully your are or planning to run Apache Web Server [if < version 1.3.14] then you need to edit you httpd.conf file
add:
ScriptAlias /php/ "c:/your/php/"
AddType application/x-httpd-php .php
Action application/x-httpd-php "/php/php"
Class dismissed!
Happy Coding }:- )