The curious and the thrill-seeking rushed to their PCs as Microsoft unveiled the preview version of Windows 8.1 at its Build 2013 conference Wednesday. It’s free, but not quite anyone can get it yet.

Before installing this Windows 8.1 trial version, it is recommended that you back up your files and settings. Once you have installed it, you will be required to activate it before October 31, 2014.

Update 7/19/2021: Windows 8.1 is long outdated, but technically supported through 2023. If you need to download an ISO to reinstall the full version of the operating ...