It's simple. You just write your php program and save it as any kind of extension. Example:
date.php
<?php
// Print out today date
echo date('Y-m-d');
?>
Go to Dos Prompt run the following command:
c:\php\php.exe c:\php\date.php
or you can cd in php directory and run
php.exe date.php
Enter the same command as you want to run in the Window Scheduler.
That's all!!!