Microsoft is losing consumer operating system market share to Apple for many reasons, but most of those reasons can be oversimplified thus: Mac OS is simple, and Windows is complicated.

Until today, even experts couldn't tell you off the top of their heads the differences between each of the many Vista versions -- or even how many versions there are -- or what the basic requirements are for the Upgrade versions. Ordinary consumers are baffled to the point of paralysis.

Don't feel bad if you still don't know which of the Upgrade proof policies above is the real one -- few outside Microsoft do. (In fact, none of them is correct.)

Microsoft created this confusion by failing to tell anyone what the proof requirement would be for using an Upgrade version of Vista.

There is a widely published workaround that enables users to install Upgrade versions of Vista without XP. It involves, essentially, installing Vista twice. Whether this work-around is considered by Microsoft as legitimate or a form of piracy -- like so much about Vista -- is still unknown.

When Bill Gates launched Windows 95 a dozen years ago, consumers understood what they were getting. It was a brand-new Windows, vastly superior to Windows 3.x, and came in exactly one version. PC users could just go to the store and buy it, take it home and install it, and they didn't need a doctorate to figure out how to do all this.

Fast forward to this week. Windows Vista launched with 10 -- count 'em, 10 -- versions. Instead of giving us a simple new upgrade path to the future, they instead gave us a homework assignment. Here are the versions:

It's obvious that Microsoft decided to extract maximum cash from consumers by micro-segmenting the market and trying to provide a different version for each. But they may end up with the opposite result. All this confusion over versions and upgrade policies will motivate unknown millions of consumers to simply stick with Windows XP or move to a Mac.

Wow!