I have never really used it but if you buy a mcafee cd and you install it do you have a key code that you have to enter for it to work or does it just somehow have that info integrated into the cd? If you download it is it a stand alone installer that you can keep on a cd or your HD and reinstall it any time? Or is it like norton where it installs from a website and you have to go back to the website to reinstall it? Can you redownload it for free? Or do you get emailed a keycode that you can just enter into a trial version?