Chances are, your PC is different from the way it was at the start of this year. In fact, because you're the kind of PC user who reads articles like this one, I'll bet your PC is different from the way it was even a few days or weeks ago: Perhaps you added or removed some software. Maybe you installed a patch or update, or allowed one to be installed automatically. Perhaps you adjusted a system setting to make Windows look or act more the way you wanted, instead of the way Microsoft or whoever set up your PC thought it should be. Perhaps you tried out a performance tweak or other system change that you read about here or elsewhere.
even though its an article from 2004, I believe the recommendations are timeless.
Langa Letter: Year-End PC Tasks - News by InformationWeek
Looking for administrator password guidelines for DrPuter in the newsgroup, I found this site, which I found extremely comprehensive and a good collection of tips about malware, spyware, etc. from an MVP.
May you have a safe holiday season and a wonderful 2007!