One of the little white lies about Windows is that it's "self-updating" -- whenever there are new drivers or systtem components available, Windows will download and install them automatically from Microsoft Update. That's only provided the manufacturer has ever bothered to make them available through Microsoft Update in the first place.
It's some kind of bizarre irony that several of the most critical drivers for my computer happen to be not available through Microsoft Update.
A little background: I'm running an Alienware dual-processor AMD Opteron system, with a Tyan motherboard. As it turns out, AMD provides a set of drivers for the chipset used by the motherboard that are not the stock drivers you'd get in a Windows installation. Windows will install and run without them, but not well, so it's somewhat in your best interest to stay up to date with such things ... provided you remember to do so. These drivers aren't offered through Microsoft Update and have to be added or updated manually. How I came to be reminded of all this is half the adventure.
After working with Office 2007 for a month or two (I love it), I noticed something odd: whenever I scrolled through a document in Word with my mousewheel, I'd get a weird visual artifact where the top or bottom few lines of the document onscreen would be repainted ad infinitum up and down the length of the window. I poked around a bit and found that it was probably a video driver problem, and since I hadn't thought to try and update my video driver in months, I went ahead and did that.
The video driver (which was for an ATI Radeon 9550) came with a set of utilities to configure the video card as well. Out of curiosity I opened them up and started checking the settings, only to find that the card's diagnostic tool was reporting that I had a "0X Speed" AGP bus. Whaaaa? Another round of poking around online revealed that this often happened if your AGP controller driver was out of date.
The date on the AMD AGP controller driver was 4/1/2002. Several of the other AMD-specific drivers were also hopelessly out of date. They had never been updated since the last time the system image was prepared.
I went "argh" and "aieee" and snagged the appropriate driver packs from AMD's site. One -- ahem, two reboots later, the system was not only free of Word weirdness but was running much faster overall. (To top it off, I also snagged an updated driver for the disk controller, which was also a year behind the curve.)
Moral of the story: Updated does not always mean updated.
I guess this also means I need to update the system image I built....

*fol* That sounds like me! Only I can't seem to find the updates for the drivers I have. *gigglefits* Oh well. I'm not running what you're running and I'm not doing what you're doing. I guess I can be a bit more patient while I continue to search.
Glad you found your drivers! *hugs*