If you've been screaming from the rooftops for Microsoft to return the Start button to Windows, you're going to be happy. On Wednesday, Microsoftat its Microsoft Build conference. The update brings a long list of new features, but most notably, the Start button returns!
Along with the announcement of Windows 8.1 and its new features, Microsoft also announced the release of a preview version for Windows 8.1. Anyone can download and install the preview, but keep in mind it's not final software and is likely to be full of bugs and issues.
To get the Windows 8.1 preview you simply need to visit this link and click on "Get it now." Currently, however, the ISO files aren't available for download, with a note on the site stating that the proper files will be available "within the next day." You can also install the preview through the Windows Store if you don't want to wait for the ISO to become available.
Microsoft has posted a Preview FAQ page to help answer any questions concerning installing the preview via the various methods, or the stability of the beta version. You'll also want to be sure to check the FAQ to ensure your system is compatible with the update, but as a general rule of thumb, if you're already running Windows 8, you'll be able to run 8.1. Make sure to create a complete backup before updating, and treat installing the update as a permanent change on your machine, as going back to Windows 8 requires a complete restore of your system (thus the need for the backup).