You don't that's why it's called deleted. And yes I am aware of techniques that allow you to see them but that would be trying to explain how to sever your arm with a pocket-knife. You don't want that. Accept you don't know and move on :) Oh and Matty, restoring also means you loose all other data that changed in the mean time ie photos and such, if you suggest that to people, at least tell them about the consequences.
easyest thing to do is to restore the pc to an earlier time
deleted history on what?