Are you experiencing compatibility, performance and reliability problems associated with Windows Vista? Well, Microsoft is hard at work delivering resolves for all your troubles. Just not yet! 938979 Vista Performance and Reliability Pack and 938194 Vista Compatibility and Reliability Pack are two updates released to a select group of testers via Microsoft Connect. Subsequently, the fix pack then leaked to the web and the download frenzy ensued. However, Microsoft reacted instantaneously. And as a result, the initial source of the leaks has removed all references of the two updates. Additionally, Microsoft has taken down the downloads.

So I guess we're still talking about compatibility, performance and reliability issues, but only for the time being. The fact that the two packs were released to testers signals that Microsoft is evolving the resolves to the point were they will meet a certain quality standard recommending them for general release. Up until that point, even if you've managed somehow to get your hands on the updates, you should exercise extreme care in installing them, since neither is ready for deployment. So Microsoft scrambling to discontinue the downloads and to limit the information available on the fix packs is actually a move to protect Windows Vista users. The updates have the potential to cause more harm than good, even though the promised benefits can appear to outweigh the inherent risks.

Reading the two lists of fixes related to the updates, you can recognize updates designed with the first service pack for Windows Vista in mind. Issues related to calculating the estimated time remaining upon copy and move tasks, to synchronization, to file corruption and to the operating system's memory manager are addressed by the updates. Essentially, Microsoft will resolve both general and specific problems affecting Vista's performance and reliability as well as various issues in incompatibility scenarios. In this sense, the updates are indeed a preview of Vista SP1, but this does not mean that they won't be made available via Windows Updates as standalone fixes, prior to the service pack.