 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.In 1996, Windows NT 4.0 was released, which includes a fully 32-bit version of Windows Explorer written specifically for it, making the operating system work just like Windows 95.