Nothing is completely deleted from the computer. While deleting the history keeps 99% of people from seeing what you did, if you're really paranoid, use a private browsing feature in your browser.
i don't think it is.And even so,there is no way to access it.I do that regularly as well.I mean i think there is a way that you can restore it,but in the meantime it'll stop anyone from seeing what you were on.