Beyond this show-stopper of a problem, one reason for not porting the software is that there would be little benefit in running Windows Server on ARM, Laing added. Server-based ARM might initially look like an easy way to cut server power usage, but it would have only a minimal impact on energy usage.

"On a server, the chip is only one part of the power consumption," he said. The motherboard, memory, network controllers and other components all consume power as well. "Even if you dramatically drop the power requirement [of the chip] there are definitely some other power requirements," he said.

Laing would not say that Microsoft would never consider developing an ARM-based version of Windows Server, but he said the company has no immediate plans for doing so now.

Microsoft had been developing Windows Server 8 for about three years, Laing said. It had a broad set of goals to reach with this release, such as cloud compatibility and automation of routine tasks across multiple machines. "No longer does a server run on a single machine," he said.

Laing assigned engineers not to develop specific technologies, but rather to solve common problems that may cover a range of technologies, such as moving virtual machines from server to server without any downtime. "We tied all the pieces together, so we would have a more consistent release," he said.