That depends on who might some day come looking. If it's just the average person, maybe even the average IT professional, simply deleting the history via the browser is enough. If you're really paranoid, I think everyone has copied Firefox's Private Browsing mode by now, where basically the browser doesn't even store history or anything like that. If you're really paranoid about privacy, you shouldn't be using IE or even Chrome. IE is made by Microsoft, which tends to default to permitting anything and everything until it comes back to bite them and Google may have made its start as a search engine, but these days makes the bulk of its money off of advertising. I don't have any hard evidence that Chrome does anything untoward on its own, but it is tied pretty heavily into Google's other services, which in turn serve up plenty of text based ads and the like. Firefox is the only independent browser out there for the most part.