Microsoft may have not made much headway when it comes to its mobile strategy, but there is no alternative plan, Chief Financial Officer Peter Klein told an investor conference on Wednesday. "It's less 'Plan B' than how you execute on the current plan," he said when asked about other options to its Surface tablet and Windows Phone pursuits. Klein said Microsoft's new Windows 8 platform is perfectly suited to offer a wide array of screen sizes, from 4 to 13 inches. He added that the company's foray into making a tablet will help, rather than alienate, its hardware partners because it "allows us to innovate in ways in which we couldn't before."