A department of the US government has forbidden its employees from upgrading to any of the major new Microsoft software products. Windows Vista, IE7 and Office 2007 are all on the black list of the US Department of Transport (DOT).

In an email to staff, the man in charge of the DOT, Daniel Mintz, placed "an indefinite moratorium" on the upgrades, citing inflated prices and serious compatibility issues as the reason.

"There appears to be no compelling technical or business case for upgrading to these new Microsoft software products. Furthermore, there appears to be specific reasons not to upgrade," he said.

"Microsoft Vista, Office 2007, and Internet Explorer [7] may be acquired for testing purposes only, though only on approval by the DOT chief information officer."

The DOT ban is applicable to over 15,000 workers who use computers, while Mintz's memo indicates that the Federal Aviation Administration is taking similar measures.