Windows NT / OS2 did have more security as it was meant for shared environments, but even there, corporations ended up using stuff like Novell NetWare to get the actual networking services.
Windows 2000 was the first version of consumer windows based on the NT kernel instead of the DOS / Windows 95/98/ME based systems. I still remember running around the office updating windows 2000 machines to service pack 4 to protect us against the first real massive virus "ILOVEYOU".
Edit: Still on first coffee, sorry about the ramblings