Windows NT 3.51 used the older Program Manager interface inherited from Windows 3.x. Meanwhile, Windows 95 had debuted to mass market success with its revolutionary new shell. Microsoft's goal with NT 4.0 was to bring that familiar, modern UI to the more powerful NT kernel — creating an OS suitable for both desktop users and corporate servers.

The project was codenamed Shell Update Release (SUR), sometimes also referred to as Tukwila. A key and controversial architectural decision was made during development: the graphics subsystem (GDI) was moved from user mode into kernel mode. This dramatically improved graphics performance but meant that a buggy or malicious graphics driver could destabilise the entire system.

NT 4.0 was released to manufacturing on July 31, 1996, followed by retail availability on August 24, 1996. Server editions followed in early September 1996. The release was well received, particularly in corporate environments where its stability over consumer Windows versions was valued.

NT 4.0 became the longest-running version of Windows NT until Windows 2000's release four years later. Over its support lifecycle it received six official service packs, plus a Security Rollup Update.

On 12 February 2004, over 30,000 source files for Windows NT 4.0 were leaked onto the internet. The leak was later traced back to Mainsoft, a company that had licensed the NT source code to port Windows APIs to Unix.

• Start menu and taskbar
• Windows NT Explorer (later known as File Explorer)
• “My Computer”, “My Documents” shell folders
• Recycle Bin, shortcut icons, desktop as a folder
• Per-user Start menu shortcuts

• Space Cadet Pinball (3D Pinball)
• Font smoothing (anti-aliasing)
• Full window drag
• High-colour icons
• Wallpaper stretch-to-fit
• Desktop Themes utility

• CryptoAPI — Microsoft's cryptography API, introduced here
• DCOM — Distributed Component Object Model
• TAPI 2.0 — first TAPI release on Windows NT
• Task Manager — the familiar Ctrl+Alt+Del task switcher
• Winsock 2 and improved TCP/IP stack
• DirectX support (limited)
• Internet Explorer 2 bundled
• Partial Bluetooth 1.0 support (Service Pack 5+)

One of the most significant under-the-hood changes was moving the GDI and graphics drivers from user mode into kernel mode. This yielded a major performance boost — particularly important as NT competed with Windows 95 on the desktop — but at the cost of stability: a buggy display driver could now crash the entire OS.

The standard desktop edition targeted at business users and power users. Supported up to 2 processors and 4 GB of RAM.

The server edition included IIS 2.0, Microsoft FrontPage 1.1, NetShow Services, and Remote Access Service. Supported more processors and higher RAM limits than Workstation.

Enhanced server edition with support for up to 8 processors and clustering capabilities via the Microsoft Cluster Server (MSCS) add-on. Targeted at mission-critical enterprise deployments.

Added multi-user remote desktop capabilities — an early precursor to what would become Remote Desktop Services in later Windows versions.

A modular variant designed for embedded systems and appliances. Had the longest support lifecycle of all NT 4.0 editions, with extended support lasting until July 11, 2006.

Released in 1997, the Option Pack added server components including IIS 4.0, Personal Web Server, Transaction Server, Message Queue Client, FrontPage 98 Server Extensions, and Windows Scripting Host. Required SP3 or later. This was the only option pack ever released for a Windows version.

NT 4.0 was one of the most architecturally diverse versions of Windows ever released:

• x86 (IA-32) — PC/AT and PC-98 compatible systems
• DEC Alpha — supported until August 1999 (dropped after SP4)
• MIPS — only SP1 was released for MIPS
• PowerPC — SP2 was the final service pack for PowerPC

NT 4.0 was the last version of Windows to support Alpha, MIPS, and PowerPC. Non-x86 Windows would not return until Windows RT (ARM) with Windows 8.

• 486 processor or better (386 support dropped from NT 3.51)
• Minimum 16 MB RAM
• 110 MB hard drive space
• VGA or better display
• CD-ROM drive

Early builds of NT 4.0 would crash on processors with a CPUID value higher than 3. This kernel bug was fixed in Service Pack 6.

Create a folder on the desktop and rename it sequentially to each of the following:

1. and now, the moment you've all been waiting for
2. we proudly present for your viewing pleasure
3. The Microsoft Windows NT Product Team!

Implemented in SHELL32.DLL, with names stored as XOR'd hashes (key: 0x95). Early builds showed “SUR Shell Team” — a nod to the Shell Update Release codename.

On February 12, 2004, over 30,000 source files for Windows NT 4.0 were leaked onto the internet. The leak was traced back to Mainsoft, which had licensed the source to port Windows APIs to Unix.

Microsoft originally planned a seventh service pack. It was cancelled in April 2001 and replaced with the Security Rollup Update, signalling the final push to move customers to Windows 2000 and XP.

NT 4.0 was one of the first Windows versions to ship with 3D Pinball: Space Cadet, sourced from Maxis' Full Tilt! Pinball. It survived through Windows XP before being quietly dropped in Vista.