I stumbled across an article over on Slate (by way of a Slashdot story) that attempts to answer, in a nutshell, the essential question PC users the world over ask themselves “Why can’t Microsoft get security right?”. The article, unfortunately, is too brief to accurately describe why MS can’t get it right, but it does feature some good advice:
What can you do to protect yourself? Besides avoiding Microsoft products, one way would be to use substitutes whenever possible. If you run Windows or the upcoming Vista, use a different e-mail program, browser, and/or media player than the ones that come in the box. Stay up to date on patches and anti-virus software. And the next time Bill G. promises to make software that is so fundamentally secure that customers never have to worry about it, ask him what decade he plans to release it.
Good advice, that. If you’re setting up a PC for friends or family, why not install Google Pack? That should handle things nicely, as it will even keep Firefox, Ad Aware, etc. up to date, meaning (most important of all) you won’t have to.