You're going to see a lot of tablets powered by Windows RT, Microsoft's new lightweight operating system. Our advice: don't buy any of them until Microsoft irons out some early bugs and more apps are available for the OS. Right now, very few apps are available for RT, which looks like Windows 8, but can't run standard Windows applications. Apps that do run on RT perform inconsistently, with some taking advantage of the OS's touch-friendly new Windows user interface, and others, such as the RT version of Microsoft Office, forcing you back into the familiar Windows Desktop. There are even two versions of Internet Explorer, one for the new UI, and one for the Desktop. Windows RT does get some things right; it has better multitasking than you'll find on any other tablet OS, and the new UI, which has been derided as impractical in a desktop environment, feels natural and intuitive on a touch-based device. However, the UI is also available on Windows 8, which can run the millions of applications written for the Windows Desktop environment. Manufacturers are rolling out laptops, desktops and tablets for Windows 8, and that's a much better option for most people. For RT to be a viable mobile OS, more apps need to be built that work seamlessly and effortlessly in the touch-based universe. If and when that happens, you should take another look, and we will too.