If you are having problems getting certain updates installed on Vista, there are two places you can look to troubleshoot:
%windir%\windowsupdate.log, a log file for Windows Update events
%windir%\Logs\CBS\CBS.log, a log file that tracks events to the servicing stack
These log files include the following fields: Time/Date Stamp, Message Severity, Message Source, Operation Type, and Main Text.
Mitch Tulloch was lead author for the Windows Vista Resource Kit from Microsoft Press, which is the book for IT pros who want to deploy, maintain and support Windows Vista in mid- and large-sized network environments. Mitch was also the author of Introducing Windows Server 2008 and technical project lead for the Microsoft Office Communications Server 2007 Resource Kit, both books also from Microsoft Press. For more information on these and other books by Mitch, see www.mtit.com.