Windows NT 3.51 build 1057.1

Windows NT 3.51 build 1057.1 is the official RTM build of Windows NT 3.51, released on 30 May 1995. It was compiled for the x86, PowerPC, MIPS and DEC Alpha platforms, and shipped in both a Workstation and Server SKU.

Installation
The CD for Windows NT 3.51 is not bootable, and requires the use of three included boot disks. Also, you can upgrade from a previous version. By running  with the /b switch, you can bypass the floppy disk requirement.

Compaq OEM
A Compaq OEM version of the Workstation SKU, dated 7 June 1996, was dumped on 20 September 2017 by Internet Archive user galeharpring.. It is a bootable CD, but the boot sector has been modified to check for a Compaq system. The CD contains the base system, drivers, and Service Pack 4 installation files in the English language.

The CV of Chris A. Caudle, a former Compaq developer, references work done for this OEM version:

Software developer for “Microsoft Windows NT from Compaq,” custom OS installer shipped with Compaq SmartStart installation and integration tool. Utilized C and some C++ to implement a tool which integrated custom Compaq drivers into the Windows Server installation without requiring customer intervention. Implemented installation utilities for Windows Server in C and C++. Utilized Microsoft internal development tools to modify and rebuild Windows NT 3.51 setup code to enable customized installations. Localized (i.e. designed for easy translation) code shipped in five European languages and Japanese.

It also references a Compaq OEM version of the Server SKU. "Release 2.50" of this version (dated 12 December 1995) was dumped on 23 June 2020 by Internet Archive user nt351. Unlike the newer Workstation CD, it is not bootable (there is x86 real-mode code at 0x200 in the ISO, but it does not comply with the El Torito standard), and is like the NT 3.1 Compaq OEM in that it is multilanguage and has the registry hives encrypted. It contains the base system, drivers, and Service Pack 2 (and NT 3.5 Service Pack 3) in the English language, and the base system, drivers, and Service Pack 1 (and NT 3.5 Service Pack 2) in the French, German and Spanish languages.