If you look back, the personal computer started as a standalone machine with a more or less stable operating system. The idea that you could upgrade the hardware and software was a fundamental part of the appeal, but the manpower implications meant this was avoided as far as possible.
If you look forward, the personal computer will clearly be a networked, Web-enabled device which may be upgraded on a daily basis. Almost every time a user logs on, their system software will be refreshed with one or two small files or patches, installed automatically from the server.
The problem is that most businesses seem to have a computing model that is 20 years out of date. They still think of buying a PC running a fixed operating system for a fixed price and then using it forever - or at least, until the user gets to the point of throwing it out the window.
While it is currently just about possible to get by with that kind of model, it clearly will not be in the future. And it doesn't really matter whether you are in the pro- or anti-Microsoft camp. Microsoft.net looks the most likely winner in the network-dependent future, but IBM's Websphere and every other "marketecture" is heading in the same direction. Some systems, including AOL and Tivo personal video recorders, work that way already.
In a Web-based networked future, the idea of buying a boxed copy of Windows 95 and using it for 10 years is untenable. Software will be licensed on a subscription basis, and the main option will be whether to take the refreshes from in-house servers or directly from the software supplier or a third party. The Windows Update Centre, which appears on a Start menu near you, is just the first step in that direction.
I am not saying users should not haggle over prices. What I am saying is that you should start haggling with a view of how things will develop over the next 20 years, not what happened 20 years ago.
Jack Schofield is computer editor of The Guardian