Why did Microsoft break my machine?

Last night my machine was configured completely correctly. I could see all the files on my Windows Home Server from my Vista box and from my MacBook.

Today I can still see the home server from my MacBook but the Vista machine downloaded and automatically installed an 'update'. Now the files on the network drive are visible in the folder view but some cretin has decided that I need to be protected from them.

Needless to say, the machine does not tell me why the access attempt is denied or how to fix it. Thes two questions are part of the critical gap in security usability.

This really exemplifies a naive approach to usability that is unfortunately rather too common. The naive approach to usability assumes that the user's 'problem' is that they are stupid and its the job of the designer to help the poor stupid user by removing as much confusing knowledge as possible.

The result of this approach is systems that often test quite well in controlled lab settings that are designed to test the users reactions over short periods against a series of tasks designed to show the user using the product in exactly the way the designers intended but fail completely whenever an eventuallity arises that the designers didn't think of.

Ask your system administrator is not an acceptable response in a system dialog being presented to someone with administrator privileges.

Update I have now discovered the actual cause of the problem - a printer that had been disconnected was reconnected. This was hardwired to the same IP address as the home server which caused the interference.

But it is still the responsibility of the machine to identify these issues and report them, not the user. The most likely cause of the problem was the last major change to the system - the software update.