Is there any display when you power on? can you see the boot up process? or is the monitor only active after windows has loaded?
If you can see the boot up process, then you should be fine with formatting
Are you using any kind of antiviruses? Check its settings. What are the software you have running in the background (see task manager)?
Also from where are you reading these audio/video files? HD? ODD? Network?
Finally you can check if...
I think it's the fan related...It could be dirty or the ball bearing needs to be oiled...Or it could be the hard disk spinning down...anyway, since its fairly new, take it to the service center and let the techies fix it for you