For years, tech enthusiasts have been compiling hotfixes into unofficial service packs for Windows, offering brave users a quick way to update their operating systems before Microsoft finishes its own. But for Vista, Microsoft is warning users not to trust these third-party roll-ups.

In a blog entry posted Tuesday, Vista product manager Nick White specifically mentions one such “Service Pack 1 preview” for Microsoft new operating system. The fact that Microsoft is preparing SP1 for Vista is a given, but the company has remained coy about its potential release date.

In turn, some bloggers at have taken it upon themselves to create their own. While such updates would have gone largely unnoticed in the past, social news Web sites have helped spread the word through eye-catching titles such as “Blogger Posts Windows Vista SP1.”

“Those of you who’ve been closely following discussions on Windows Vista will quickly notice that what is posted consists of some material already available on Windows Update and some hotfixes that we give out on a case-by-case basis, along with a lot of speculation about what may and may not be included in SP1,” explained White.

He adds that the blogger utilized Knowledge Base articles on Microsoft’s support site to compile a list of available hotfixes, stitching them together in one update with previous Vista updates. It’s standard policy for Microsoft to include hotfixes it has created for very specific problems into the next service pack.

“However, a service pack is not just a compilation of hotfixes and security updates, so don’t make the mistake of thinking that the set of fixes offered in this particular blogger’s list represents a preview of the service pack itself,” White says.

But even if it’s not a complete preview of Vista SP1, what’s bad about installing fixes created by Microsoft? Potentially quite a bit, notes White.

“These hotfixes represent specific fixes for specific customer scenarios and typically have not undergone full regression testing. When they are integrated into a future service pack, they will receive full regression testing and beta testing. So, installing a collection of unnecessary hotfixes may cause more problems than are fixed.”

White additionally emphasized that Microsoft is not yet ready to discuss Vista Service Pack 1, saying that the company will have plenty to say when it’s ready. That stance has irked some businesses looking for future guidance, but Microsoft has remained adamant that Vista is ready for prime time and waiting on the first service pack is unnecessary.