During his last speech, Bill Gates not only spoke about the first and second digital decade, but, as usual, he unveiled some data about Windows Vista, the latest OS launched by Microsoft in January last year.

According to Bill Gates, Microsoft Vista has sold more than 100 million licenses of Windows Vista since the operating system was launched.

Maybe 100 million seems impressive but let’s take a quick look at the facts. The world's largest software company spent some 6 billion dollars and 5 years to develop the programme and is offering a smorgasbord of different versions designed to fit everyone from the web-surfing granny who needs just basic functionality to the media and gaming- obsessed geek who wants his computer to do everything except pour his coffee. Prices range from 199 dollars for Vista Home Basic to 399 dollars for the Windows Vista Ultimate with all the bells and whistles.

According to Microsoft, Windows Vista is superior to Windows XP from all points of view. Vista users can actually expect several thousand new functions, Microsoft claims. Most of them are hidden underneath the hood, so to speak. One eye-catching element is the new graphical interface, dubbed Aero. It is remarkable first for its semi- transparent windows. Open several windows at once, and you can still see which other folders and documents are open beneath them.

This is not exactly trailblazing in the world of operating systems, though. Transparent windows are also available in Apple's Mac OS X and with various Linux versions. Also, Microsoft says Windows Vista is the safest operating system ever. The users’ login system management has been modified almost completely, applications no longer have easy access to Windows’ basic components and these are but a few of the changes the Redmond company has made.

Microsoft has wanted to lose its label of unsafe OS so badly, acquired through Windows 95 and Windows 98, that it invested heavily in security, purchasing companies and products and even starting a bit of a conflict with established producers such as McAfee and Symantec.

Let’s recap: the best OS so far, 1 billion clients’ worth of market, virtually no competition, intense marketing efforts. You might not agree with me, but personally I would have expected Microsoft to announce at least 150 million sold licenses.

In July last year, Ballmer said that Windows Vista boasted at the time with more than 60 million legal licensees. This means that since July until Gate’s speech Vista has sold only 40 million copies or close to 9 million licenses per month.

In this rhythm, I think that it is hard to believe that Microsoft will meet its goal of more than 200 million copies of Windows Vista sold by the end of 2008.

On the other hand, Microsoft is already working on Windows Vista SP1, the major update of the operating system, and maybe after it will be released the adoption rhythm of Windows Vista will increase.