Microsoft Knowledge Base article 948343 lists eight reasons why Vista RTM (aka "original Vista") users might not be offered Vista SP1 through Windows Update. As you might expect, some of them are blindingly obvious:
If you're already running Vista SP1 (or a pre-release version of Vista SP1), Windows Update's not going to offer it to you again. D'oh!
Right now, only users of English, German, Japanese, French, and Spanish versions of Vista can download Vista SP1. User of other languages must wait until later to get Vista SP1.
If you run Vista on a corporate PC, your company might be using the Service Pack Blocker Tool to delay installation.
However, some causes are a bit more subtle and require a bit more work to fix.
Bad Drivers, Bad! Update These Drivers, or You'll Never See Windows Vista SP1!
KB948343 finally gives us a list of known drivers that prevent WU from offering Vista SP1. Products with problem drivers include:
- Realtek AC'97 audio
- SigmaTel audio
- Creative Labs Audigy audio
- Conexant HD Audio
- Authentec and UPEK fingerprint sensors
- Intel integrated graphics
- TI Smart Card Controller
- Sierra Wireless AirCard 580
- Symantec Endpoint Protection and Network Access Control clients
Logitech QuickCam also has a problem, but it's a problem with a Microsoft-provided Vista driver - in other words, don't blame the camera! KB948343 has a complete list of affected driver versions and solutions, most of which can be summed up this: get updated driver versions!
CheckSUR to the Rescue!
Vista SP1 might not be offered to your system if your computer's file system, registry, or system files are fouled up. The new CheckSUR update, which I wrote about in the announcement of Vista SP1's release for download, is designed to fix problems that prevent Vista SP1 or future updates from running. If Windows Update offers you this update (KB947821 explains it in detail), run it to get your system in shape.
Got vLite? Maybe You Shrank Vista Too Much!
Another major reason Redmond lists for not being able to get Windows Vista SP1 via WU is if you're trying to update a vLite-customized version of Vista. As we warned you on page 2 of our vLite writeup:
Keep in mind, though, that a vLite-customized version of Vista isn't compatible with SP1.
This doesn't mean that everyone who used vLite to install Vista is up a creek until they do a reinstall of Windows Vista: only those who used vLite to discard Vista components need to perform a reinstall. If you fall into this category, read the next paragraph for some good news about vLite.
If you used vLite only to integrate hotfixes and drivers, you can remove a registry key to make your system "see" Windows Update's offering of Vista SP1. See the vLite Service Pack page for details. This page also ofers a link to a method you can try for creating a Vista SP1 install image from your Vista RTM disc through a process called "reverse integration."
Wait Your Turn, SP1!
The last major reason you might not be seeing Vista SP1 in Windows Update is that you might need to install other updates first. Make sure you install all recommended or important updates displayed when you check for updates. After that, if there are no other problems with your system, Windows Update will display Vista SP1 in your WU list - and you can update your system.
(a hat tip is in order to Neowin.net forum poster Chrono951 for the KB article link)