Today, businesses use networks consisting of intranets, Internet sites, and extranets, all of which extend the network, requiring increased system security. In addition, confidential information may be stored on mobile computing devices, which are subject to theft and loss.

Windows 2000 provides end-to-end security that lets organizations integrate systems both inside and outside the corporate network boundaries, while providing complete access control and data protection. Security features include advanced techniques for identifying who is accessing the system, including the use of digital "keys" to access selected data, and a single ID that permits users to access not only their own computer, but also other shared resources (such as printers or files) on the corporate network, the Internet, or even a business partner's network.