Computers, like everything (including people) need preventive maintenance.  Here is a list of what I think a person should do; I'll try and "dumb it down" and make some pretty stupid analogies, as you all know I have a tendancy to do....

I run basically a four step maintenance plan:

Weekly check - this is to be done every week.  It really doesn't take any time whatsoever, and could be compared to doing the dishes, if you just let them pile up, pretty soon you have all kinds of bugs running around.

Monthly check - This check is to be performed WITH in addition to a weekly check. This maintenance is sort of like the once a week (month) house cleaning.  All the floors are swept and vacuumed real good, and all the junk laying around is put away and stored where it should be. I know my mom would go through her coupon pouch about once a month, updating the coupons to make sure they were still valid. Updating your computer operating system is sort of like keeping your coupon file up to date, if it is expired it isn't doing you any good.

Quarterly check - This check is to be performed in addition to a monthly and weekly check.  This check mainly does a health check of your hard drive, and just ensures it is running in top form. Just like the lawnmower, every once in a while, you have to check the gas, oil and make sure it is running smoothly; same goes for your hard drive.

Annual check - Time for a good ol' fashioned garage cleaning!!  This check is to be performed in addition to a Quarterly, Monthly & Weekly check. This check will have you check and clean your computer and also run some basic diagnostic checks at the end to make sure all is running smoothly.