The original operating system Gates bought was called QDOS, which was "quick and dirty operating system". He intelligent hired people to expand on it and add features and switches to make it more marketable as MS DOS. He ruined several good, much better, operating systems, such as DR DOS. He also tried to corner the browser market by striking deals with computer companies who would pre-install Windows 3.1 and ensure that their Internet Explorer icon was prominent on the screen. It didn't work, and Netscape still ate their lunch.