Microsoft (MSFT) is betting big on Windows 8 as the platform that will propel it into the post-post-PC era, but the software giant has a lot of work to do according to a recent study. In a poll of 1,200 adults in the United States conducted by The Associated Press and market research firm GfK, more than half of respondents had never even heard of Windows 8. Of those who did know about the new Microsoft operating system, 61% had little or no interest in buying a new computer that runs Windows 8 and only 35% thought it would be an improvement over earlier versions of Windows. Microsoft launched Windows 8 and Windows RT this past Friday alongside its new Surface tablet.