The memorandum from DOT chief information officer, Daniel Mintz, is dated January 17 and notes that there appears to be no compelling technical or business case for upgrading to these new Microsoft software products.

In fact, as the memo explains, there appears to be specific reasons not to upgrade. Those include upgrade costs, compatibility concerns, limited funding, and a forthcoming move to a new headquarters.

This memorandum establishes an indefinite moratorium until further notice on desktop/laptop computer software upgrades to Microsoft Vista, Office 2007 and Internet Explorer version 7 it states, adding that the software can only be acquired for testing purposes, and only with the approval of Mintz.

A further memo is due to be issues within 180 days that will explain the department’s desktop and laptop roadmap and migration plans for 2008 and beyond.

While Vista was released to businesses in November 2006 it is not expected to see widespread deployment for some time. Research firm Gartner has advised its clients to spend 18 months testing, planning and piloting before large-scale mainstream deployment.

Gartner expects that Windows Vista Business will be installed on just 4% of all the world’s PCs by the end of next year. In 2008, deployment will nearly quadruple to 15%, and then increase to 28% the following year. By 2010, fewer than half, or 39%, of PCs worldwide will be running the OS.

It has also been reported that the US Federal Aviation Authority is investigating a move from Windows XP to Linux desktops running Google Corp’s recently released Google Apps Premier hosted service, rather than Vista.

Meanwhile the UK government agency responsible for technology in education warned schools and colleges in January against deploying Windows Vista and Office 2007.

The overall evidence points to a significant number of issues that need to be addressed before Vista should be considered for deployment in educational institutions the British Educational Communications and Technology Agency (Becta) report noted, adding: Becta has not yet been able to identify any realistic justification for the early adoption of Office 2007 across the educational ICT estate.

Microsoft did not respond to a request for comment on the DOT memo by press time.