The Enterprise and Ultimate versions of Vista, due out in early 2007, will include a new graphics system called Aero. The interface, derived from games programming, will offer greater stability and reliability and a new user interface, Microsoft said.
But Chris Ingle, European systems group consultant at analyst firm IDC, said enhanced graphics capability was pushing up the cost of commodity PC hardware.
Using the desktop specification from Microsoft and Dell, Computer Weekly has calculated that the recommended PC for Vista could cost users £350 more than a typical business PC running Windows XP SP2.
Brian Gammage, vice-president at analyst firm Gartner, said, "An enterprise looking to buy new PCs for general business applications will find no business justification in spending extra on Aero-capable video hardware."
But Microsoft said, "Aero is a constituent part of Vista, providing an easy to use and easy to learn user-interface that is likely to make all users, regardless of their circumstances, more productive and more effective."
Describing the price increase facing organisations that want to deploy Vista-ready PCs as "horrendous," Clive Longbottom, service director at Quocirca, said users will need to bring back cascade policies where power users are the first to get high-spec machines, and these are cascaded down through the company when machines are replaced.
Richard Edwards, senior research analyst at Butler Group, said the hardware cost premium for running Aero would reduce over time.
"In three years' time, when Vista is expected to be mainstream, PC motherboards will have integrated graphics accelerators [to run Aero]," which will greatly reduce the cost of the hardware, he said.
Aero is designed to overcome many of the shortcomings of Windows XP and improve the readability of screen text.
Computer Weekly's calculations were based on Dell's Optiplex GX620 business desktop. Other PC manufacturers showed a similar price differential.