A new Forrester Research report on the future of the PC suggests tablet devices will in five years represent almost a quarter of all sales. Maybe, but there's plenty of room for other form factors as the personal computer becomes the equivalent of the TV with one box in every room of the house besides a multi-purpose device provided by employers.

The PC has changed a lot in the 20 years or so I've been covering this business where perpetual motion is a given. When I started out, the PC was a big beige box that retailed for two and a half grand. If you wanted a laptop you could add on another grand. The latest operating system or application would mandate a hardware upgrade and RAM cost about 25 quid a megabyte. Windows at least let you play around with colour schemes and doodle but these were workhorses and not much else.

Multimedia added the ability to play your CDs but it was only with the rise of mobile computing and the internet that usage patterns changed radically. Quite quickly, the PC became the great all-rounder of electronic devices, equally at home with fun stuff as a dull Excel workbook. Prices fell through the floor and today, whatever the dullards of Brussels might say, the PC is the great bargain and an odd sort of tribute to capitalism of our age. For £300 you get a beautiful modern marvel and old PCs are -- and this in itself is problematic -- seen as disposable items.

Today, there are over a billion computers in use, according to Gartner data. They are the modern equivalent of the ticking of the clock and birdsong, almost as much a utility requirement as electricity for many of us. Will the tablet format see another giant wave? Maybe, even if the Wintel army have been trying and failing to perfect the slate style for much of the last two decades. Certainly, Apple innovations have often filtered down to the Hoki-Koki brands in the past.

But the real trend in PCs is that they become ingredient devices for particular purposes. It seems absurd, for example to buy an internet radio when any old PC can be used for the same purpose. Carphone Warehouse already 'gives away' PCs in exchange for internet subscriptions and it can't be long before a supermarket or other mass-market company offers a free PC to court loyalty. A Tesco tablet for repeat online shoppers? It can't be far off and at that point the PC will boom again.