For people complaining that "Start" isn't a great choice, perhaps there's something better, but I can't think of anything. You need a small word that implies, "Click here to do something or find something." and in that regard, I think "Start" is a good choice.

On the other hand, I think there were few ideas worse than "My Computer", etc., not the least of which is the fact that it took Windows application software about 10 years to get consistently good at handling paths with spaces in their names.

Of course, the worst UI thing Microsoft ever did was hiding file extensions by default. That might be the worst UI decision in all of history.

> That might be the worst UI decision in all of history.

The Windows 8 touch-first start menu with a hot corner instead of a button, applied to their Server OS, that I assume most accessed through RDP was pretty horrific.