While Windows NT includes robust security features, NT Server has come under a number of attacks, the success of which has been due primarily to bugs in the operating system, not fundamental architectural flaws. Microsoft's past response to security problems was less than ideal as well. But Microsoft made an impressive turnaround over the last year, implementing measures that have established NT as a secure operating system and improved the company's standing. Remaining issues include NT Server's support for the less-secure LAN Manager authentication protocol and the lack of a fully functional directory that provides a common foundation for all security functions. While NT can stand some improvement, Microsoft has taken its responsibility for security seriously, and is fielding a secure product with NT 4.0 and the appropriate service packs.