Before Microsoft overhauled the Windows interface with its Metro design language, it attempted to sell tablets with the standard Windows 7 interface to combat Apple's iPad. One of the first and most hyped Windows 7 tablets the company touted was HP Slate 500, a device that ultimately failed to reach much of an audience. According to a New York Times article, that failure actually paved the way for Microsoft's Surface tablets.
While the project started out smoothly, the tablet was soon "completely ruined," according to former Microsoft and HP executives, when HP's manufacturing organization began acquiring parts that were sub-standard. By the time the tablet was complete, it was "thick, the Intel processor it used made the device hot, and the software and screen hardware did not work well together, causing delays whenever a user tried to perform a touch action on its screen," the Times writes.
According to the report, Microsoft continued to work with third-party partners in an effort to create an iPad rival, but it continued to run into disagreements with those partners over issues such as price and design. At the same time, partners such as HP "fumed at Microsoft" for not creating Windows software that was better suited for touch-enabled devices. Part of Microsoft's lack of commitment to these tablet devices was because the company had already begun work on Windows 8, which would be a more touch-friendly operating system.
The report indicates HP's Slate 500 failure, along with the failure of its WebOS tablet, led Microsoft to begin investing in its own hardware development. Microsoft's hardware focus led to the use of magnesium in Surface's case, a decision made to rival the lightweight aluminum found in the iPad.
Source: The New York Times