When u delete a file from an operating system, the electronic data of the file itself is not removed from the hardisk. It's just that the OS file system is not pointing to that file anymore. This applies even to reformatting. When Windows tell you that if you click OK, all data will be lost, that's bullshit for computer n00bs. But overwriting data is sure-bye-bye.
Go download TuneUp Uilities at www.download.com. It has a recovery utility which allows you to recover most of your files even ones deleted from reformatting.
MooKu
Is there a limit to the amount of data a computer can store and delete then?