Google hasn't gone anywhere much with its Chrome browser, so why does it fancy a crack at taking on Windows in 2010? Have they gone mad and are their pockets deep enough?

The obvious answer is that it is doing it because it can. Windows has seen off the challenge on netbooks from Linux but that was a confused array of different installs that were plonked on to the lowest-end netbooks and then sold by shop staff who'd barely heard the word ‘Linux' before netbooks appeared.

Google, on the other hand, has big budgets, a single install and plenty of traction in its other assets to push its Chrome OS as a viable alternative to Microsoft. People have heard of Google, indeed they probably use as many or more of its products than they do Microsoft's nowadays, and Google also has a model that allows them to give people boring software such as the operating system without having to charge for it.

(The UK RRP for Windows 7 is, believe it or not, £149.)

Presumably, Chrome will be basic, simple to use, targeted at the 85 percent of home PCs that are used simply to browse the Internet and run the odd application, in other words utterly of the early 21st Century. Does the user need Windows to do all this? Not really, and Microsoft knows it, which is why I suspect they will be forced to come up with a free started edition themselves, perhaps a reinvention of Windows XP or its successor.

It's been said before, but operating systems are a concept from the ark in an age when most of a PC's underlying services could be bundled on a ROM chip, and people spend most of their time using browsers built from bits of software that can for the most part be downloaded. It's not quite a simple as that - Windows includes drivers for a huge array of peripherals - and vendors have become used to writing their software to its APIs. But the complexity of Windows is barren.

If Chrome starts on the half dozen netbooks that take most of the sales, then ties in with a few major laptop vendors, the fact that you can't reliably put it on legacy PCs with their array of hardware won't matter. A slow attrition will cut the Windows market share.

What is driving the obsolescence of Windows is not, in the end, Chrome or any other rival, but the Internet itself. The Internet has changed software and the way we think about it, and the leery reaction to Vista and even Windows 7 in part reflects the way this new environment has changed the expectations of the users.

Users will keep paying cash to keep running an OS because it guarantees to all their apps, so Chrome isn't going to take over the world. But It's hard to see the $150 - or £150 - operating system sticking around for the next decade.