Windows 3.1 build 068

Windows 3.1 build 068 is a Release Candidate build of Windows 3.1. The build is mentioned in an internal Microsoft document from 1992-02 and is listed in a French Microsoft Knowledge Base article. The legitimate build was later leaked by users on BetaArchive on 2017-11-24. The leak was modified by the original leakers from a group called, WARES, and modified parts of the GUI setup. This is also the first build that says you need to reboot your machine to have all the options take effect.

The document only says this build was released to testers on 1992-01-24.

The French KB article describes an issue when Word for Windows 6.0 is started on this build - a general protection fault (GPF) is encountered in. This issues also happens on builds 70 and 71 and potentially other builds from the 0xx range according to the article. Task Manager features full-screen warnings that resemble a BSoD (in this build they are black) that are nearly identical to the ones used in the RTM.

According to Andrew Schulman's article titled Examining the Windows AARD Detection Code from 1993-09-01, this build contained the infamous AARD code (build 61 is also said to contain it) and was labeled as "pre-release build 3.10.068" and dated 1992-01-21.

Fake Leaked Build (2013)
A heavily modified copy of Windows 3.1 build 068 originated from betaguy224 and was later leaked by Battler. The build was eventually declared to be fake, as it combined files from the real build 068 mixed into other builds, and was removed from the BetaArchive FTP in 2013-07. This included a bug that made DOS programs cause a fault resulting in a BSOD. It is still widely available online.