When Dick McGraw checks Windows Update, he wonders which patches he should download and install.
It's confusing. Microsoft throws a lot of stuff at you, often with little information. And somehow you have to figure out what you really need, what you might like, and what Microsoft wants you to have for their own purposes.
It doesn't help that most of the updates have totally useless names. Without looking it up, can you tell me why you may or may not need Windows Vista (KB950124)? I can't, either.
You can actually display a useful description of any update. In Vista, double-click an update for the description in a pop-up windows. In XP, click the + next to the update name to expand the list and show the details.
It's also useful to consider the level that Microsoft assigns each update. Vista updates come in three levels:
* Important: Most of these updates are security fixes that you really need to safely use your computer. Unfortunately, Microsoft occasionally throws something into this group that they really want you to have for their reasons, not yours, such as Windows Genuine Advantage (sic).
* Recommended: Nothing horrible will happen if you skip these, but you might miss something that will make your PC work better. Read the descriptions and make your own decision.
* Optional: You might occasionally find a useful driver update here, but more likely you'll just find marketing hype.
XP only has two levels:
* High Priority: This is pretty much the same as Vista's Important category--most of what you get here really is important. It's worth noting that if you're still using Internet Explorer 6, the upgrade to IE8 is a high priority upgrade. There's a reason to that--IE8 is significantly more secure--but it's a big change and some people hate it (see Remove Internet Explorer 8).
* Optional: Divided into separate Software and Hardware sublevels, this combines useful but not vital updates, drivers (although not many), and useless hype. Use your judgement.
Most updates, for any version of Windows, are not cumulative. This is true even for the Important and High Priority ones. If they were cumulative, you'd only have to update one of them. Sometimes Microsoft releases a cumulative update and removes several others from the list.
And the big service packs are always cumulative. In fact, while I was researching this article, a long list of Vista updates was replaced with one: Service Pack 2.