With the great development of information technology over the last few decades, today multinational companies and small scale enterprises increasingly rely on computer networks to run their business more smoothly and efficiently. However, modern business networks are becoming increasingly vulnerable to malware attacks due to security system flaws and careless employee behavior. The Operating System used by companies can have a great influence on their network security. According to a study A Brief History of the Windows Operating System by Curtis, Microsoft announced the development of Windows in 1983 for its own operating system called MS-DOS. Windows 1.0, the very first version of Windows, was released in 1985 and it used ‘gadgets’ like calendar and calculator. The second version of Windows, Windows 2.0, was released in 1987 and it introduced two programs such as MS Excel and MS Word. Windows 3.0 was released in 1990 and it continued until 2001. Windows 3.0 was characterized by the introduction of virtual memory, multitasking programs, and improved graphics. Microsoft released Windows 3.1 in an effort to include necessary fixes and to improve font functionality. Subsequently Windows 95 was designed for promoting compatibility and user-friendliness, and it was marked for the change from 16-bit to 32-bit. The next version was Windows 98, and it focused particularly on internet connectivity and internet connection sharing. Windows 2000 played a significant role in improving the user experience by increasing the number of plug and play devices compatible with the OS. The next version of Windows, Windows XP, is the most widely recognized Window OS as it was appealing to both desktop and laptop users. The next release, Windows Vista, was a failure because of high system requirements and severe performance and security issues. Learning from the failure of Windows Vista, Microsoft introduced Windows 7 in 2009 that focused on speed, stability, and minimal system requirements.