In 1985, Gates and Microsoft took another risk. They released the Microsoft Windows operating system. This was Microsofts answer to a similar operating system introduced by Apple in 1984. At first, many people complained that Microsoft Windows wasnt as good as the Apple version. However, Gates continued to press the open PC concept. Microsoft Windows could run on a variety of PC compatible machines, while the Apple operating system only ran on Apple machines. Microsoft won the operating system battle and was soon installed on nearly 90% of the worlds personal computers.