It's been a long wait, but it's finally here.

When Windows 8 users log into their devices today, they'll get a prompt to download the newest version of the OS. It's a lot of the same, but a little of things that make a big difference: the Start screen is redesigned, Bing has been built in, users can boot the desktop, and there's smart SkyDrive syncing. If you're already using Windows 8, updating should be easy—otherwise you still have to buy the OS if you've been holding out on upgrading. (You're not alone if you've been waiting for Microsoft to fix its bugs.) Updating will save all of your desktop and Windows-8 style apps, yet with any upgrade, it's worth backing up your stuff. Microsoft has set up updated Windows apps for the 8.1 launch that will be released today, so when Windows users upgrade, they can expect those apps to appear. For those who have already updated to the Windows 8.1 Preview version, they'll have a slightly different experience: if they updated Preview from the Windows store, they can download the final version today. If they clean installed Windows 8.1 Preview, they'll need to reinstall Windows 8 so they don't have to purchase a new license key, since it won't activate without one with a clean version of Preview.

[via ABC News]