What happened I lost everything!!??

I am so bummed I have no clue what happened. I traveled to my friends in another state I turned on my Laptop and everything was wiped away. All my documents, pictures, video's and even my web pages were wiped cleaned and all new IE Firefox broswer needless to say, I am shocked. :eek: My favorites all gone.

I was having issues with the wireless connection but what the heck does it have to do with wiping everything clean?

Help! I am in tears.:(

Is there a way to get it all back?