Windows inbuilt task scheduler is really a worth tool. I have tried many third party task scheduler but when comparing the easiness and accuracy windows scheduler is the best.
In windows 8 you can get the task manager by navigating as given below
Start -> Apps -> Control Panel -> System and Security -> Administrative Tools ->Task Scheduler
In windows 8 you can get the task manager by navigating as given below
Start -> Apps -> Control Panel -> System and Security -> Administrative Tools ->Task Scheduler