Microsoft Windows, the operating system which has dominated desktop computing for decades, is in danger of collapsing, according to analysts at Gartner.

Microsoft's flagship product, which runs the vast majority of the world's PCs, has become so bulky and ill-equipped for the challenges of modern computing that it risks becoming obsolete, a pair of senior analysts at Gartner have said.

Threats from new web-based models of software delivery, a shift towards low-cost computing, and a reluctance on the part of companies to upgrade their machines to new operating systems for potentially limited benefits, have all contributed to the possiblity that Microsoft's dominance of the desktop may crumble, they said.

The increasing complexity of Windows has meant that the release times for new versions have become unpredictable, Michael Silver and Neil MacDonald, two VPs at Gartner, said. Windows Vista, the latest version, has 50 million lines of code, more than double the number of the 1996 version of the software.

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Microsoft's focus on newer and larger versions of Windows also failed to respond to the significant growth in PC shipments in the developing world, the analysts said. Growth in developing countries, where governments and other buyers are keen to keep costs down, is running at 16 to 24 per cent, compared with 2 to 8 per cent in mature markets.

This was a factor in Microsoft's decision to extend the availability of the starter edition of Windows XP - the precursor to Vista - until June 2010, two years beyond the cut-off date after which manufacturers in Western markets will no longer be able to pre-load XP on their machines, they told the Gartner Emerging Trends Symposium in Las Vegas.

"For Microsoft, its ecosystem, and their customers, the situation is untenable," Mr Silver and Mr Macdonald said in a presentation entitled 'Windows is Collapsing'.

"It takes Microsoft too long to introduce new versions of Windows and once a new version is released, it takes significant time for the ecosystem to support it and for the release to stabilise. Organisations need to wait for that support and stability, and then deal with the enormous task of deployment and management for increasingly nebulous benefits."

But Windows was becoming unsuitable as an operating system (OS) for other reasons, they went on. It made diminishing sense to have a single, overarching operating system capable of supporting any application a user might need when new techniques meant that computers were much more flexible, they said.

Using a technology known as virtualisation, for instance, computers are effectively able to draw down from a central server the ability to run an application as and when they needed it. This has led to the idea of an 'adaptive OS' or a 'just enough OS', they said.

According to a Gartner survey in 2006, a majority of organisations anticipated that 6 per cent of their desktop computers and 9 per cent of their laptops would be running on Vista by the end of 2007, but a similar survey last year indicated that just 1 per cent of desktops and 3 per cent of laptops had migrated to the new system.

Microsoft, which derives 56 per cent of its revenues from licences for programs such as Windows and Office, is also under threat from a new model of software delivery known as 'software as a service', where companies and consumers can use programs via the web, and store their information on servers elsewhere.

Microsoft is already competing fiercely in the 'software as a service' market, and last month, for instance, released a version of Office which enables people to create documents using programs like Word on the web, so that they can readily be shared with - and edited by - others.

But it faces tough opposition in the form of companies like Google, which have already released a range of web-based products for both consumers and businesses in an attempt to break Microsoft's dominance of the market.

In a statement, a Microsoft spokesman said: "Microsoft disagrees with Gartner on the state of Windows. Unfortunately much of the data presented was based on relatively small sampling of Gartner conference attendees and doesn’t align with more rigorous research."

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