That's because with Longhorn, Microsoft plans to offer three different graphical interfaces, each requiring a different level of graphics card.
"This is the first time we've had a tiered user experience based on the hardware you are running," lead product manager Greg Sullivan said during an interview at the Windows Hardware Engineering Conference (WinHEC) here.
The top-of-the-line interface, code-named "Aero Glass," will have transparency and other advanced three-dimensional shading features but will demand a high-end video card with at least 64MB of video memory. The midlevel "Aero" interface will offer most of the improved graphics abilities and will require just 32MB of video memory.
Both Aero and Aero Glass will also require DirectX 9.0 support, AGP 4X for external graphics cards and a Longhorn graphics driver.
For those systems that lack such a powerful graphics card, Microsoft will offer a "classic" interface, designed to replicate Windows 2000, the mainstay of today's corporate desktops.
Although Microsoft detailed the graphics requirements for Longhorn, it did not, as it, give public guidance on what types of hardware will be either required or recommended to run Longhorn.
Instead, Sullivan said, the company is talking privately with computer makers and other hardware companies, as it tries to finalize its plans for the OS. The arrival of Longhorn has also been, making the need for such requirements less urgent.
Sullivan did say that "the overwhelming majority" of systems being made when Longhorn ships will be capable of running the operating system. The OS will also run on relatively new machines made before Longhorn arrives. "The expectation is that if you have a relatively new PC, you should be able to take advantage of the OS," Sullivan said.
The graphics requirements are not merely for show, Sullivan said.
"When you have a terabyte of local storage, potentially, a rich way to relate and gain (access) to the data becomes very important," Sullivan said. "We're not doing 3D in the (Windows) shell because it is cool--but it is cool."
Independent technology analyst Peter Glaskowsky said the hardware requirements appear not to be overly stringent and that the OS should run on most modern machines. "Certainly, by the time it comes out, I think almost anything being manufactured will make the grade," he said.