Over the course of a couple of days I’ve struggled to get an Exchange Server to install an update. What I stumbled upon was an idea I’ll share now. After repeated failures pointing to insufficient privilege, I discovered that while I couldn’t run the .msp package “As Administrator”, instead I could run an elevated command prompt that way and launch the .msp from that context. Well guess what? It worked!
While this was for Exchange 2007, I believe the concept is universal with any stubborn updates for any Microsoft products. This means you have to manually download the patch locally too of course.