PC operating systems have been a route to riches for many people over the last 30 years or so. The current market leader, and almost the monopoly supplier, is the US company Microsoft, which recently launched their latest operating system called Windows 7. Why have they done this? What are the alternatives? If you are a Microsoft operating system user, should you upgrade?

What Are PC Operating Systems?

When you buy a Personal Computer (or a Mac, the Apple proprietary variant) it usually comes with some basic software to turn it from an inanimate object into something that can be loaded with applications software. Applications software enables you to do things like type, or calculate, or browse the internet. But a PC needs some software to be able to run these applications and that is the operating system software - the OS. It’s a bit like an orchestra; it needs some musical notation on paper, and a conductor to make, well, music.

When you switch on a PC, it automatically loads the OS from the hard drive into semiconductor memory - memory that is fast but forgets everything when the computer is turned off. It typically takes several minutes to do that, during which time you can make tea, study a knitting pattern or file your nails. Some users avoid this wait by never shutting down their PC by telling it to 'hibernate,' at the end of a session. Hibernating copies the current state of the PC to the hard drive and when it restarts it simply fetches the saved state from the hard drive rather than starting from scratch. It's as if the orchestra paused mid-tune, but didn't break for tea and biscuits, avoiding a lengthy retune period.

The Entry on Operating Systems contains more details.

The OS then allows the user to start applications and use peripherals like a printer or a router for broadband internet access. In fact it tells the PC what devices are available, such as a keypad, a mouse, a display, a Wi-Fi adapter or dongle. The members of the orchestra are told where to sit, which instrument to play and what part of the musical score to use.

There are three main PC OSs available today, out of the many hundreds that have been created:

Windows

In very early PCs, both IBM and IBM-compatible, the OS was called DOS (disk operating system) and it was supplied by Microsoft. On IBMs it was called PC-DOS, while on IBM-compatibles it was MS-DOS. It was developed, after several years, into Windows. It became the first mass-market OS for PCs and retains that position, with approximately 95% share of the OS market. There have been several releases, beginning with Windows 1.0, moving on via several more iterations to Windows 95, 98 and Me, then to Windows XP, Windows Vista and in October 2009 to Windows 7. Windows Vista, with around 25%, and Windows XP, with around 70% share of the market, dominate the PC OS scene. The latest version (Windows 7) improves on speed and introduces some new features, such as touch screen navigation, although, with the correct driver, older versions of Windows can also provide this feature.

Mac OS X

Apple developed its own OS called Mac OS followed by Mac OS X, which is now in its tenth release known as Mac OS X version 10.6. This has around 4% of the PC OS market and is bundled with Apple Macintosh PCs. (It cannot be used on other PCs). The latest version improves on the stability, speed and efficiency of previous releases and reduces the amount of disk space needed. Continuing the musical analogy, this amounts to a chamber orchestra, rather than a full symphony orchestra space, but with the same musical output.

Linux

Linux, with around 1% of the PC OS market, is open source software, developed from Unix, a mainframe OS, and may be downloaded free of charge, depending on the 'distribution' used. The most popular is Ubuntu, followed by Fedora. Linux distributions are bundles of software, making up the OS, offered and supported by different organisations. The software may be 'free' (mostly) but the support is not. Linux updates are more frequent, arriving every six months, and the latest was released in October 2009. The most popular distribution is called Ubuntu 9.10 (released 29 October 2009).

The Linux community has a reputation for being 'techie' and more interested in the underlying code than the user benefits. This is unfair. Most supercomputers, mobile devices and servers use Linux software. They are late into the PC sector, mainly because Microsoft's OS has been bundled with PCs as a matter of course, but Linux is now gaining share in the PC OS market. Several major PC manufacturers now offer Linux as an alternative to Windows, bundled with their machines. Comparisons between Windows and Linux can be surprising, particularly when a performance comparison is carried out between the two operating systems. The concluding remarks from these tests are reproduced below:

As you should be able to tell from the scope of the features we've discussed, Windows 7 marks a significant point of maturity in the development of Windows, and is what the much-maligned Vista should have been three years ago. There's still a distinct lack of innovation, but the improvements to system stability and performance are what's going to matter to most users. And most users of Windows are businesses. They're not interested in eye candy, Twitter integration and hardware acceleration. They just need Windows to be a sober working environment that doesn't get in the way of helping people work.

And this is where Linux can make a big difference. There's nothing in Windows 7 that Linux can't do, and in most cases, do it better. Our machines are quicker and more efficient. Our desktops are more innovative and less static. Our apps are more powerful, cheaper and less partisan, and Linux security has never been better. But best of all, we have complete control over the future of Linux, and its success or failure at the hands of Windows 7 is in our hands.

The Need for Upgrades

Upgrades to the PC OS are provided for a number of reasons:

• To improve on usability by introducing new features to the graphical user interface

• To improve stability by reducing random system crashes

• To reduce the time taken to do things

• To improve system security, preventing virus and other malicious software from infecting the PC from a network

Software support is, of course, vital. (The orchestra needs to be told where the next venue is, and to be taken there). Software suppliers phase out support for older releases over time, to reduce their costs, and to encourage users to upgrade. This means that patches to fix problems will no longer be issued (which includes Microsoft's so-called Service Pack releases, which aggregate many patches into a package that may be downloaded in one go, rather than as separate mini-upgrades).

All of the OSs are built on a software core or kernel. In the case of Linux, it is a Linux kernel, developed from Unix, which is used on some business computers, servers and supercomputers, because of its stability. Microsoft's later releases (from XP onwards) are built on its NT (for New Technology) kernel. Mac OS is built on a Unix core. The improvements to the OS are built on these, and add user interface improvements or other attributes to make the OS better at doing its main job of running applications. Going back to the orchestra analogy, each upgrade removes dead members of the orchestra and repairs broken instruments.

Windows XP, built on NT 5.1, will be supported until April 2014. Windows Vista and Windows 7, built on NT 6.0 and 6.1 respectively, are the current OSs. All other versions of Windows are no longer supported¹.

Another reason for upgrades is to take advantage of improvements in hardware and the availability of new services and applications. (Someone wrote some new musical scores). More memory, faster processors and new applications, like internet access, have all contributed to the need for better OSs. (A new musical instrument was invented). Competition between the OSs has also led to new releases, but that is secondary, given Microsoft's domination of the market.

What Should You Do?

If you don't own an Apple Mac, and the chances are that you don't, you really have two alternatives; Windows and Linux. You probably have a version of Windows on your PC, and that is most likely to be XP. As support from Microsoft extends as far as 2014, you don't need to do anything, especially if you are happy with your PC's performance. Other versions of Windows for the PC (Vista and 7) will be supported beyond 2014.

If you are buying a new PC, you could choose Linux or Windows, or if you want the latest in thinness and graphical user interfaces, an Apple Mac. The choice is yours. If Linux, you may get it free from one of the downloadable distributions, but you will have to pay for support, should you need it. (An advantage here is that you will not need to buy anti-virus software, as Linux is inherently safe, and no one writes viruses for it).

If you choose Windows 7, for example, it will be supported free of charge for the next ten years (probably), but you need to ignore Microsoft's biennial blandishments to upgrade. Remember, 'if it ain't broke, don't fix it’. And, if you do decide to upgrade your PC, be aware that some of your software may not be supported by the new OS. This includes both applications software and drivers for your peripherals - you may find that you can't use your old printer any more because there's no driver for it available for the latest OS. It's worth checking this out most carefully.