Click Start button, type “task scheduler” (without the quotation marks) :
Give a name and description of the task in the Wizard window and then click Next button:
In next Window, select when you want the alarm, then in the Action windows option, select Start a program :
Then Browse for any sound file (*.wav, *.mp3 etc) :
Click Next and then Finish the wizard. Setting up of your own alarm clock using Windows 7 Task Scheduler is done.