Operating System Update pains

A second-tier German professional basketball team has been relegated to an even lower tier as a result of being penalized for starting a recent game late—because the Windows laptop that powered the scoreboard required 17 minutes to perform system updates.

From ArsTechnica

I'm a firm believer in keeping machines up to date I think most people can relate to the experience of an update occurring at the worst. possible. time.......

What's your worst experience?