Screenshots of the build show the version number 9374, and this particular version has begun to appear on the Internet for a few days already, with a post on the WinForum.eu message boards touting that this particular build’s system32 contents and the boot.wim have been leaked. I guess that would also mean the leaked screenshots have just increased their credibility rating in terms of being real. We do see the name “Windows 8.1 Pro Preview” being bandied around in the leaked screenshots, which could lead to Microsoft working on a free preview version of Windows 8.1 in due time later this year.