Windows NT 3.5 build 683

Windows NT 3.5 build 683.1 is the official Beta 2 build of Windows NT 3.5. The Workstation edition of this build was leaked by a warez group in 1994, but the floppy disks were mistakenly dumped in 1.44MB images instead of DMF (1.68MB), resulting in unrecoverable data loss. This means most of the disk images are broken and the Workstation build is unusable. The floppy version of the Server edition on this build was leaked on the Chinese website BetaWorld on 19 October 2019, then ISO image was found and uploaded to BetaArchive on 27 September 2020.

This build is also mentioned in the file  from Windows NT 3.51 build 854.1.