The fourth generation of operating systems saw the creation of personal computing. Although these computers were very similar to the minicomputers developed in the third generation, personal computers cost a very small fraction of what minicomputers cost. A personal computer was so affordable that it made it possible for a single individual could be able to own one for personal use while minicomputers where still at such a high price that only corporations could afford to have them. One of the major factors in the creation of personal computing was the birth of Microsoft and the Windows operating system. The windows Operating System was created in 1975 when Paul Allen and Bill Gates had a vision to take personal computing to the next level. They introduced the MS-DOS in 1981 although it was effective it created much difficulty for people who tried to understand its cryptic commands. Windows went on to become the largest operating system used in techonology today with releases of Windows 95, Windows 98, WIndows XP (Which is currently the most used operating system to this day), and their newest operating system Windows 7. Along with Microsoft, Apple is the other major operating system created in the 1980's. Steve Jobs, co founder of Apple, created the Apple Macintosh which was a huge success due to the fact that it was so user friendly. Windows development throughout the later years were influenced by the Macintosh and it created a strong competition between the two companies. Today all of our electronic devices run off of operating systems, from our computers and smartphones, to ATM machines and motor vehicles. And as technology advances, so do operating systems.