Looks like over on the WSUS product team blog they’ve addressed some of the more common questions we get on the Microsoft .NET Framework 3.5 SP1 update.  I’m glad they did too, because 95% of the questions I get about WSUS these days always have something to do with that update.  Anyway, I have their intro below but if you want to read their entire post and get all the details you can do that here . We’ve noticed some confusion about the recently released updates for Microsoft .NET Framework 3.5 SP1.  So, let’s see if we can help clarify the differences in the packages.  These updates apply to x86 and x64 computers.  The detailed update descriptions describe both the platform and OS architecture that apply for each of the updates. You’re also likely wondering about the differences in the update titles