For some time we’ve had the luxury of a catalogue of patches, service packs, hot fixes and more, but it’s astounding how many people don’t seem to know about it.
With that in mind, please feel free to browse to http://catalog.update.microsoft.com and search for just about anything.
You may search for a technology – here I’m searching for Exchange, or a particular hot fix that you know exists but may not be visible on the Microsoft download site, Small Business Server has a few of those :p
The next time you’re stuck for a hot fix or anything else that you know exists, but you don’t know where to find it, have a look at http://catalog.update.microsoft.com. The FAQ section helps define what can be searched for and I’ve used the site to locate drivers, hot fixes and much more.