Microsoft Windows is the number one software business, comprising $110 Billion of worth. Following Windows by a close margin is the popular Office Suite. Amazing how one piece of software could be so well received by the community. Microsoft protects it’s Windows OS from competition and piracy so much, probably because without it, it’d just be another software company out there.

Windows, now valued at $110 billion, has surpassed IBM’s Middleware ($107 billion). The figures come courtesy of Trefis, a financial analysis firm who track the most popular stocks in the US. Trefis has been tracking Microsoft’s Windows sales over the past year and has published its results for all to see. “While most of the businesses continued to retain their position, Microsoft’s Windows Operating System emerged as the single most valuable software business segment in 2010. Microsoft Windows Operating System (at $110 billion) surpassed IBM’s Middleware, which at $107 billion now stands at a comfortable second,” states Trefis.