You do not have a large selection of operating systems for a home desktop computer. Off the top of my head, I can think of six: Microsoft's versions Apple's versions Linux variants and OpenBSD Amiga OS OS/2 (not a serious contender today) Zeta (BeOS) They all have their pros and cons, but that's not as important as you might think. Computers are tools and the important question is, "What do you want?" If it is important to you to have access to the largest selection of current software as well as brand new programs as they are released, then you should get Windows. If you just hate the monopolistic practices of Microsoft, but want the fancy MS Office applications, then you will probably be very happy with Apple. If you have older hardware, you are technically competent, comfortable working with file systems and OpenOffice applications, then a Linux variant can make you happy. Security is misunderstood. If you are online, then you are at risk no matter which OS you use. Hackers seek stardom! The most widely used OS is the one they want to break. Security is a dual-edged sword. MS is the biggest target, but it is also the OS with the most experience fighting hackers. So, what do you want?