Go to Startmenu->All Programs->Accessories->System Tools->Task Scheduler->create Task
In the new window we having 4 options
1. General (Give the Task name and for testing you can select “Run when User is logged in“)
2. Trigger (You can Select the running interval as “daily,weekly,monthly”. )
3. Action (This is most important part.Select a Mozilla firefox as the “program/script” and in the Argument provide the URL to fire with Mozilla firefox like http://www.waytocode.com/mycron.php).
Create a task give Running time in Trigger setting.Then in Action setting option in the “Program/Script” command textbox type
and in the “Add arguments (optional)” type