Microsoft is preparing an update to Windows 8 for release later this year. It says the changes are designed to address complaints and confusion with the new operating system. Windows 8 is the most radical overhaul of Microsoft’s operating system since Windows 95 came out nearly two decades ago. It was revamped to embrace the types of touch-screen controls popular on smartphones and tablet computers, devices that are siphoning sales from the desktop and laptop PCs that have been Microsoft’s traditional stronghold. Windows 8 was released with much fanfare in October, but got a lukewarm reception from consumers. Part of the problem is that Windows 8 tries to be all things to all people. It’s designed to respond to touch-screen controls, but it also works with traditional mouse and keyboard commands. It offers a new layout that resembles tablet computers, but it also has a desktop mode that looks like previous versions of Windows. What results is confusion.