You are getting a lot of potentially bad advice from a lot of people who haven't taken the time to understand your situation first.
It is possible that recovering deleted data from the hard drive might be necessary, but until some basic questions are answered first, it is impossible to know.
While it doesn't hurt to turn that computer off until we figure out exactly what the situation is, the first and most important question that needs to be answered was asked by BitBlue and is still unanswered:
What bitcoin client were you using?
If you were using blockchain.info, Electrum, or Armory, then you are probably being sent down the wrong path to recover this.
If you were using Bitcoin Core or MultiBit, then your options for recovery become more limited.
If you are using some other wallet entirely, then it is difficult to know what your situation is until you let us know what wallet it was.