Task scheduler, when, why and how.

Recently, I found two reasons that led me to write this post. The first reason is a friend asked me to help him to set up an application that needs to be run periodically, and the second is, I was handling an old project, which needs to execute an application every night, but it was done in windows services with a thread with timer, my guess was that the previous developer looked that was easier that scheduling a task, seriously?. Textually, I found this post. " definition a Windows Service.
Service
A program, routine, or process that performs a specific system function to support other programs, particularly at a low (close to the hardware) level. When services are provided over a network, they can be published in Active Directory, facilitating service-centric administration and usage. Some examples of services are the Security Accounts Manager service, File Replication service, and Routing and Remote Access service.
". So, unless we have a real reason to use a windows service as a scheduled task otherwise the best approach is to use a Task Scheduler.