A. NT actually stands for Northern Telecom but
Microsoft licensed it and in the Windows sense stands for New Technology.
Its also interesting to note its heritage
RSX -> VMS -> ELN -> NT all major designs of David Cutler
Also VMS +1 letter = WNT (Windows NT) :-) (aka HAL and IBM in 2001)
Another theory is that the NT acronym orginally came from the Engineers working on it. The acronym stands for N-Ten, the code name for the i860 chip that NT was being tested on.