īased on discussions with our customers, we have come to the conclusion that Service Pack 7 is not needed, but that an easy way to deploy our publicly released security fixes would be appreciated by many of our customers.
Since then, Microsoft has been supporting our customers with a series of hotfixes in response to specific concerns, including security vulnerabilities. Windows NT 4.0 Service Pack 6a, the most recent service pack for Windows NT, was released in November of 1999. In a support document titled "Update on Windows NT 4.0 Service Pack 7", Microsoft stated that:
There was a 7th Service Pack planned, but it was canceled and Security Update Rollup 6a was released instead.
There were 6 service packs released for Windows NT 4. Its technology later merged into the Remote Desktop Protocol by Microsoft. The Terminal Server edition (codenamed Hydra) was released roughly a year after Windows NT 4's RTM. Windows NT 4.0 Server (Server, Server Enterprise Edition, Terminal Server) were designed to serve web pages to multiple clients using IIS. Windows NT 4.0 Workstation was designed for general desktop use. It has been found out that the only difference between the two editions (Server and Workstation) lied only in the Registry and the missing Server files. There are two editions of Windows NT 4.0. 3.15 Post-Service Pack 6a Security Rollup.