The release candidate for Windows 7 is now available for download, and techies everywhere are busy kicking the tires on the new operating system. But as the folks over at Finnish anti-virus firm F-Secure observe, Microsoft persists in misleading users on the true nature of file types, by hiding file extensions of known file types in Windows 7. The default behavior of Windows Explorer in every version of Windows from Windows 2000 through Windows Vista is to represent files using icons, and to hide each file’s extension type, such as “.txt” for text files, “.doc” for Microsoft Word files, and so on. But as Security Fix has noted before, this is a usability vs. security decision that Microsoft should have reversed long ago, and it’s disheartening to see this behavior persist in Windows 7. That means that our average Windows user — when he or she opens up their “My