Running Nonnative Applications in Windows 2000 Professional

The Windows 2000 Security subsystem protects interprocess communications but not processes that run in environments that emulate other operating systems. An application process running in the Win16 emulation environment behaves like an application process running on a Windows 3.1–based computer. It shares information with processes running on other computers in the same way — with the same reduced protection — that an application running on a Windows 3.1–based computer shares information.

This can have unintended consequences if you have assumed that all information on the computer is protected by the more advanced security available in Windows 2000. Applications in emulation environments are potential weak points in system security if they are allowed to share critical resources over the network. For this reason, emulation must not be run on computers that store sensitive information.