Windows NT 3.1 build 340

Windows NT 3.1 build 340.1 is the October 1992 pre-release build of Windows NT 3.1, available in both Workstation and Advanced Server editions. The latter was leaked on 3 November 2017 by The Distractor on BetaArchive. It is the earliest leaked build of the Advanced Server version of Windows NT, at the time still called "LAN Manager for Windows NT".

This build is often mislabeled either as build 319.1 or 328.1, which are actually file versions of its kernel files ( and  ). NTFS now works in this build.

This build changes the desktop background color from grey to teal, which has been used until Windows 2000 build 1773.1. It was then still used in the Windows 9x line of operating systems until Windows Me build 2429.

Around the release of this build, the now well-known error in the processor detection routine appeared, preventing installation on the Pentium II and later without modification. It made its way into the final release and persisted into Windows NT 3.5. It was finally fixed around Windows NT 3.51 build 1002.1.

File differences
The following files have been introduced or removed compared to build 297: