When Windows Vista SP1 rolled out as an optional update via Windows Update last month, some users had problems with one of the required prerequisite updates: KB937287, which updates the Servicing Stack.
Some systems got stuck in an endless reboot/reinstall cycle which prevented users from ever getting Vista SP1 offered via Windows Update. Workarounds have been developed (some are listed in the previous link, or you could follow this link to the standalone install versions of the update), but for users who didn't want to install the update manually or download the full install version of Vista SP1 (available here), the problems with KB937287 were annoying - and resulted in the update being pulled from Windows Update.
Here's the good news: starting Tuesday 4-8-08, KB937287's coming back to Windows Update with a precursor update (KB949939) that will check for problems and correct them before KB937287 is installed. If you already have this update installed or already have installed Vista SP1 manually, you're home free. But if you've been waiting for a fix, Windows Update will deliver it to you starting tomorrow.
Other Vista updates due on Patch Tuesday include:
Once all of the details for Patch Tuesday updates are released, we'll have the details here.