Windows NT 4.0 build 1381.2

Windows NT 4.0 build 1381.2 is the official Service Pack 1 release of Windows NT 4.0, which was released on 16 October 1996. This was the last version of Windows NT for MIPS-based systems.

Source code leak
Most of the source code for this version of Windows, as well as about fifteen percent of Windows 2000, were leaked in February 2004. The code is mostly complete, excluding cryptographic related components such as rsa32.dll, which were excluded from archival due to licensing issues, as the code was adapted from a reference implementation by RSA themselves. This is not the case in Windows 2000 and later, as Microsoft rewrote rsa32.dll to use a functionally identical, but entirely originally written, implementation.