Windows NT 3.51 build 856

3.5.856.1
Build of Windows NT 3.51
OS familyWindows NT
Version number3.5
Build number856
Build revision1
Architecturex86

Windows NT 3.51 build 856 is an unleaked build of Windows NT 3.51, mentioned in the file LICENSE.TXT from the Windows NT 4.0 source code.

First you will need the header and libs from NT build 856 or later to get the
latest license API and LsaLogonUser changes.