Pauls Sams, Blizzard's chief operating officer, has called for Microsoft to put its backing behind the Windows operating system as a gaming platform.

Sams said he thought the company needed to shift its emphasis from the Xbox 360 and focus more on the PC.

"Their gaming focus is very much on the [Xbox] 360. And that makes sense, cause they're a hardware manufacturer as well as a software developer. And so they've got a lot of money and investment tied up in that system," said Sams.

"But I kind of look at it and say to myself that it would be great if they put more emphasis on the Windows operating system, certainly probably the most prominent operating system in the world. Even more so than console boxes. I think that there's more that can be done," he added.