>> I believe there are a few. NT, like other multi-user based operating
>> systems make it harder for viruses to survive due to their security based
>> file systems. However, the chance of infection isn't eliminated, just
>I would have thought that the protected memory scheme would be the biggest
Well if you only consider viruses that attack files/file systems this would
be true, however the most common viruses do not. Low level viruses attack
before the protected memory scheme is in place (when it boots, an Intel
processor is in "real" or 8086 emulation mode with no protection). The
rings are not a problem since they are not there at all.
Coming up fast, the "macro" viruses also are not impeded in any way since
they do not rely on the NT environment to function, using instead the
context of the application to spread (WORD being the most "popular").
Finally, the fact that virus writers have not targetted NT as yet just
means exactly that and probably for the same reason that OS/2 is relatively
virus free (with the same caveats as above), not that it is inherantly