MojoKid writes "Microsoft's Windows "Blue" 8.1 update has been long-awaited. Those who've been using the base OS since launch have no doubt been anticipating some of the enhancements that are coming. At the moment, Windows 8.1 is available only as a preview, and if you are looking to give it a try, there are a couple of things to be aware of. The most important is the fact that once you upgrade, you can't easily downgrade — so you may wish to try the update in a virtual machine or on a test machine if possible. In addition, your current product keys will not work, so you'll effectively be turning your activated OS into an evaluation (it's assumed that once 8.1 goes final, we'll be able to update using our original keys). That said, Microsoft's free update offers a slew of enhancements like a new Start Screen, the return of the Start Button, even quicker shutdown and restart, boot to desktop, quicker integrated search and Skydrive enhancements. All told, Microsoft's new OS release is a more than worthy successor for end users but now Microsoft really needs to work on getting developers on board."