Microsoft’s Windows 8 was greeted with a mix of excitement, skepticism and uncertainty when it launched on Oct. 26, marking the first major aesthetic overhaul the Windows software has seen in its years of existence.

Prior to the software’s launch, some heavyweights in the PC industry criticized the new Microsoft software. Intel CEO Paul Otellini said the OS wasn’t ready yet, and head of Valve Gabe Newell criticized Windows 8 by calling it a “catastrophe.”

However, Microsoft CEO Steve Ballmer might have disproven some of these doubts, announcing at the company's Build 2012 conference that Windows 8 has sold four million upgrades in its first three days.

Ballmer also added that laptop sales are up by 20 percent, but emphasized that the full Windows 8 experience isn’t just about one device. According to the Microsoft CEO, the new operating system truly shines when experienced across multiple platforms.

He described the Windows 8 interface as “alive and active with information” from the cloud.

“If you want the best experience with your Windows Computer, you will own a Windows Phone,” Ballmer said at Build 2012 according to Slash Gear.

At Monday’s Windows Phone 8 event, the 56-year-old Microsoft chief was confident that Windows 8 would become a popular choice among PC users over the next year, saying that “hundreds of millions of people,” will soon be using the operating system.

But Ballmer isn’t the only Microsoft executive talking up Windows 8’s potential. Keith Lorizio, Microsoft’s VP of US sales and marketing said that about 400 million Windows 8 devices “will be active” by July 1, according to Beet.TV.

Ballmer agreed with Lorizio, saying that 400 million people will buy PCs next year. This number aligns with predictions from market research firm IDC, which said that 391 million PCs will be shipped worldwide in 2013.

The long-time PC maker entered the saturated tablet market by releasing its first-ever self-branded slate alongside Windows 8: the Surface. Pre-orders for the device sold out on their first day, backing up shipments of the $499 model to three weeks.

Like its Windows 8 operating system, Microsoft has some high expectations for its Surface tablet. The company is aiming to sell “a few million” tablets in 2013, according to ZDNet.

As Windows 8 came close to its unveiling, manufacturers such as Lenovo, Acer, Asus and Samsung began showing off their new convertible style laptop-tablet hybrids. These Windows 8 PCs combine elements of both tablets and laptops, acting as an optimal host for an operating system that encompasses both a traditional PC and mobile-centric user interface.

While Microsoft has partnered with these companies to produce Windows 8 PCs, the Surface may represent the first of many ventures into the hardware business. The possibility of a Surface phone may arise in the future, judging by the success of the tablet.  

Originally reported by the China Times and further reported by The Verge, Microsoft has not denied the idea of creating its own smartphone. However, the company has no plans to do this until next year at the very earliest.

As Mary Jo Foley of ZDNet writes: “Microsoft is in the hardware business, and [is] here to stay.”