Windows NT 4.0 is a major release of the Windows NT operating system developed by Microsoft and oriented towards businesses. It is the direct successor to Windows NT 3.51, and was released to manufacturing on July 31, 1996, and then to retail in August 24, 1996, with the Server versions released to retail in September 1996.

Date released: November 20, 1996
End of Support: multiple, click to see
Last release: Post SP6a Security Rollup on July 26, 2001
Succeeded by: Windows ME (released 2000)
Codename: Shell Update Release
Developed by: Microsoft Corporation
Windows NT 4.0 is a preemptively multitasked, 32-bit operating system that is designed to work with either uniprocessor or symmetric multi-processor PCs. It was Microsoft's primary business-oriented operating system until the release of Windows 2000. Three editions were sold - Workstation, Server and Embedded editions, and each edition featured a Graphical User Interface UI similar to that of Windows 95. Windows NT 4.0 was the last public release of Microsoft Windows for the Alpha, MIPS, and PowerPC architectures.
Mainstream support for Windows NT 4.0 Workstation ended on June 30, 2002 and
extended support ended on June 30, 2004; being succeeded by Windows 2000
Professional.
Windows NT 4.0 Server mainstream support ended on December 31, 2002 and
extended support ended on December 31, 2004; which was succeeded by the
Windows 2000 Server family.
Windows NT 4.0 Embedded mainstream support ended on June 30, 2003, followed by
extended support on July 11, 2006; and was succeeded by Windows XP Embedded.
Service Packs
Service Pack | Date Released |
---|---|
Service Pack 1 (SP1) | October 16, 1996 |
Service Pack 2 (SP2) | December 14, 1996 |
Service Pack 3 (SP3) | May 15, 1997 |
Service Pack 4 (SP4) | October 25, 1998 |
Service Pack 5 (SP5) | May 4, 1999 |
Service Pack 6 (SP6) | October 27, 1999 |
Service Pack 6a (SP6a) | November 22, 1999 |
Post SP6a Security Rollup | July 26, 2001 |
Windows NT 4.0 received six service packs during its lifecycle, as well as numerous service rollup packages and option packs. Only the first service pack was made available for the MIPS architecture, Service Pack 2 was the final release for the PowerPC architecture, and Service Pack 6 was the final release for the Alpha architecture. Service Pack 6a (SP6a) is the last released service pack for Windows NT 4.0.
Service Pack 7 was planned at one stage in early 2001, but this became the Post SP6a Security Rollup and not a full service pack, released on July 26, 2001, 16 months following the release of Windows 2000 and nearly three months prior to the release of Windows XP.
In addition to bug fixes, the service packs also added a multitude of new features such as Ultra DMA mode for disk drives along with bus mastering, newer versions of Internet Information Services, user accounts and user profile improvements, smart card support, improved symmetric multiprocessing (SMP) scalability, clustering capabilities, MMX / 3DNow! / SSE / SSE2 support, AGP support, COM support improvements, Event Log service, MS-CHAPv2 and NTLMv2, SMB packet signing, Syskey, boot improvements, WINS improvements, Routing and Remote Access Service (RRAS), PPTP, DCOM/HTTP tunneling improvements, IGMPv2, WMI, Active Accessibility and NTFS 3.0 support among others.
Features
Although the chief enhancement has been the addition of the Windows 95 shell, there are several major performance, scalability and feature improvements to the core architecture, kernel, USER32, COM and MSRPC. Windows NT 4.0 also introduced the concept of system policies and the System Policy Editor.
Other important features were:
- Crypto API
- Telephony API 2.0 with limited Unimodem support, which was the first release of TAPI on Windows NT
- DCOM and new OLE features
- Microsoft Transaction Server for network applications
- Microsoft Message Queuing (MSMQ), which improved interprocess communication
- Winsock 2 and the TCP/IP stack improvements
- File system defragmentation support
The server editions of Windows NT 4.0 include Internet Information Services 2.0, Microsoft FrontPage 1.1, NetShow Services, Remote Access Service (which includes a PPTP server for VPN functionality) and Multi-Protocol Routing service. There are new administrative wizards and a lite version of the Network Monitor utility shipped with System Management Server. The Enterprise edition introduced Microsoft Cluster Server.
One significant difference from previous versions of Windows NT is that the Graphics Device Interface (GDI) is moved into kernel mode rather than being in user mode in the CSRSS process. This eliminated a process-to-process context switch in calling GDI functions, resulting in a significant performance improvement over Windows NT 3.51, particularly in the graphical user interface. This, however, also mandated that graphics and printer drivers had to run in kernel mode as well, resulting in potential stability issues.
Windows NT 4.0 was the first release of Microsoft Windows to include DirectX as standard—version 2 shipped with the initial release of Windows NT 4.0, and version 3 was included with the release of Service Pack 3 in mid-1997. However advanced hardware accelerated Direct3D and DirectSound multimedia features were never available on Windows NT 4.0. Later versions of DirectX were not released for Windows NT 4.0. However, OpenGL was supported; it was used by Quake 3 and Unreal Tournament.
In early releases of 4.0, numerous stability issues did occur as graphics and printer vendors had to change their drivers to be compatible with the kernel mode interfaces exported by GDI. The change to move the GDI to run in the same process context as its caller was prompted by complaints from NT Workstation users about real-time graphics performance, but this change put a considerable onus on hardware manufacturers to update device drivers.
Windows NT 4.0 also included a new Windows Task Manager utility. Previous versions of Windows NT included the Task List utility, but it only shows applications currently on the desktop. To monitor CPU and memory usage, users were forced to use Performance Monitor. The task manager offers a more convenient way of getting a snapshot of all the processes running on the system at any given time.
Internet Explorer 2 was bundled with Windows NT 4. The installation of Internet Explorer 4 on Windows NT 4.0 (Service Pack 3 or later) gave Windows NT 4.0 Active Desktop and browser integration into Windows Explorer, known as the Windows Desktop Update.
Windows NT 4.0 upgraded NTVDM's x86 emulation in the RISC versions from 286 to 486. Sysprep was introduced as a deployment tool with Windows NT 4.0.
x86 versions of Windows NT 4.0 require the BIOS firmware. RISC versions of Windows NT 4.0 require the ARC firmware.
Editions
There are numerous different editions of Windows NT 4.0. They include:
Client- Windows NT 4.0 Workstation was designed for use as the general business desktop operating system.
Servers
- Windows NT 4.0 Server, released in 1996, was designed for small-scale business server systems.
- Windows NT 4.0 Server, Enterprise Edition, released in 1997, is the precursor to the Enterprise line of the Windows server family (Advanced Server in Windows 2000). Enterprise Server was designed for high-demand, high-traffic networks. Windows NT 4.0 Server, Enterprise Edition includes Service Pack 3. The Enterprise Edition saw the introduction of the /3GB boot flag, which changed the default virtual address space mapping from 2 GB kernel and 2 GB user space to 1 GB kernel and 3 GB userland. This version also sees the first introduction of cluster service.
- Windows NT 4.0 Terminal Server Edition, (known as Windows-based Terminal Server 4.0 and Windows Terminal Server 4.0 in beta builds) released on June 16, 1998, allows the users to log on remotely. The same functionality was called Terminal Services in Windows 2000 and later server releases, and also powers the Remote Desktop feature that first appeared in Windows XP and later versions of Windows. Windows NT 4.0 Terminal Server Edition, like Windows NT 4.0 Server, Enterprise Edition, includes Service Pack 3.
Embedded
- Windows NT 4.0 Embedded (abbreviated NTe) is an edition of Windows NT 4.0 that was aimed at computer-powered major appliances, vending machines, ATMs and other devices that cannot be considered general-purpose computers per se. It is the same system as the standard Windows NT 4.0, but it comes packaged in a database of components and dependencies, from which a developer can choose individual components to build customized setup CDs and hard disk boot images. Windows NT 4.0 Embedded includes Service Pack 5. It was succeeded by Windows XP Embedded. Microsoft ended mainstream support for Windows NT 4.0 Embedded on June 30, 2003, and received three years of extended support, which means that support for Windows NT 4.0 Embedded ended on the same day support for Windows 98 and Windows Me ended on July 11, 2006.
User Interface
Microsoft's Windows NT 4.0 was the first version of the NT family to feature a GUI similar to that of Windows 95. Windows NT 4.0 introduced the user interface of Windows 95 to the Windows NT family, including the Windows shell, File Explorer (known as Windows NT Explorer at the time), and the use of "My" nomenclature for shell folders (e.g. My Computer). It also includes most components introduced with Windows 95. Internally, Windows NT 4.0 was known as the Shell Update Release (SUR). While many administrative tools, notably User Manager for Domains, Server Manager and Domain Name Service Manager still used the old graphical user interfaces, the Start menu in Windows NT 4.0 separated the per-user shortcuts and folders from the shared shortcuts and folders by a separator line. One significant difference from previous versions of Windows NT is that the Graphics Device Interface (GDI) is moved into kernel mode rather than being in user mode in the CSRSS process. This eliminated a process-to-process context switch in calling GDI function, which results in a significant performance improvement over Windows NT 3.51, particularly in the graphical user interface. This, however, also mandated that graphics and printer drivers had to run in kernel mode as well, resulting in potential stability issues.
