Svenburg said that Microsoft is planning to host senior officials from the Department of Transportation in Redmond before the end of March to address the concerns the department expects to encounter in moving to the OS.

In his memo, Mintz specifically cited "lack of a compelling business case" as his rationale for temporarily banning the move to Vista, along with Microsoft Office 2007 and the Internet Explorer 7 browser.

To be fair, Mintz and other DOT officials attributed some of the department's reluctance to upgrade on the agency's planned move to a new Washington headquarters later this year.

The DOT technology executive didn't immediately respond to calls seeking further comment on the Vista moratorium.

Microsoft representatives said that like many of its largest, Enterprise Agreement-level customers, government organizations such as the Transportation Department will need to avail themselves of the software maker's compatibility and deployment automation programs to help overcome some of the perceived challenges with Vista deployment.