A. Windows NT (both the Workstation and Server) is a 32-bit Operating System. It is a preemptive, multi-tasking Operating System, which means that the Operating System controls allocation of CPU time, not the applications, stopping one application from hanging the OS. NT supports multiple CPU's giving true Multi-tasking, using symmetrical multiprocessing, meaning the processors share all tasks, as opposed to asymmetrical multiprocessing, where the OS uses one CPU and the applications another. NT is also a Fault Tolerant Operating System, with each 32bit application operating in its own Virtual Memory address space (4 GigaBytes) which means one application cannot interfere with another's memory space.
Unlike earlier version of Windows (such as Windows for Workgroups and Windows 95), NT is a complete Operating System, and not an addition to DOS.
NT supports different CPU's: Intel x86, IBM PowerPC (Not to be supported for NT5.0) and DEC Alpha.
NT's other main plus is its Security with a special NT file system (NTFS) that allows permissions to be set on a file and directory basis.