Deleting internet browsing history for good.?

I am giving my old pc to a family member. I was wondering if there is a way to permanently delete my internet browsing history, specifically email and facebook related things (pwords etc.), purchase history (credit card info...), and sites visited. I am not worried about deleting any doents (my pictures or word doents) or programs, but I would like to make sure that my internet history is gone for good. I often delete it from the toolbar (cookies, temp internet files, forms…the whole nine yards), but I know that it's still on my hard drive. I am willing to physically purchase a disk from a store like Best Buy (not an online retailer), but I would prefer a free, safe way to do it. I’m currently using Vista and Internet Explorer. By the way, I know that the feds and computer forensic experts can always recover it, you don’t have to tell me that, but there is nothing shameful, embarring, or incriminating in my Internet history, I just don’t want any personal info available.