An operating system, also known as OS, is the “bridge” between software and hardware. Programs can be run to when this process is in motion. Many devices such as personal computers, tablets and even smartphones require OS to run a program or software. There are different kind of OS currently available in the market such as Windows, Mac OS X, Linus, Unix or even the Google Chrome OS, but they have the same function which help you to process your data and documents and each of the operating system have graphical user interface (GUI) provided. Windows 1.0 is running based on DOS. When it first appeared in the market it was not as stable as expected but the easy manipulate surface make many users interested in using the OS. It was in Windows 2.0's OS that the windows company introduced the Microsoft Word and Microsoft Excel. The way it is easy to use and economically priced makes it stand out in the selling of operating systems when compared with other OS such as Mac OS. Besides that, Windows 3.0 is also supporting games such as solitaire. Windows NT was a step up version of the previous one as it allows 32 bits and is not a home version for users, instead it's a workstation but it was in here that it appeared to have the start button. Windows 95 OS actually had improved on its color and also its multimedia. It also provided the TCP/IP network to connect with people around the world. It was a huge achievement in the sales when it was introduced. Windows 98 had enhanced its speed and also the hardware supported, such as USB support. The malware, which is a software used to disturb or even destroy a computer system, appeared after this operating system was introduced. It actually encountered some problem when Windows wanted to introduced its own web browser in this operating system. Windows ME (Millennium Edition) had unfortunately been a failure to the public as it was not as stable as the previous Windows 98 and even worst. After many