Windows NT 3.1
Redmond, Washington, U.S.
In 1993, Microsoft released Windows NT 3.1, the first version of the newly-developed Windows NT operating system. Unlike the Windows 9x series of operating systems, it is a fully 32-bit operating system. NT 3.1 introduced NTFS, a file system designed to replace the older File Allocation Table (FAT) which was used by DOS and the DOS-based Windows operating systems.