Dumping Old Internet Content Permanently

[KayfabeMan]

I'm wondering how I can permanently remove all the old websites and internet files and info. from my computer?? [ie. all of the old websites I've ever visited and such].

Basically, I want to get rid of all the past sites I've visited, so no matter where on my computer you look you can't find them. I'm thinking of giving my computer to a friend for a little while, and I want NONE of that information on it at all.

I don't care about my personal files, as they're all business related and such; just don't think that any sites that I visit are anyone's business.

How can this be done??

Thanks so much.