Windows 8 Consumer Preview which is a Beta version of Windows 8 was released on 29th February 2012. Before that I was using Windows 8 Developers Preview which was the first Beta version of Windows 8.
Windows 8 is the new version of Windows that may be released some time this year. A lot of people think that Windows 8 is different from other versions of Windows, but it is not really. Most of the Windows XP and Windows Vista software is working on Windows 8. And you can also run software for Windows 2000,98 and 95.