STATUSNOTIMPLEMENTED

STATUS_NOT_IMPLEMENTED is an NTSTATUS error code used in Windows NT-based operating systems and their subsystems to indicate that a requested operation is not implemented by the target component. It signals that the function or feature is recognized by the API but not provided by the specific object being acted upon, such as a driver, filesystem filter, or system service.

Usage contexts include kernel-mode and user-mode interactions. A driver, subsystem, or API may return STATUS_NOT_IMPLEMENTED when an IOCTL, system call, or higher-level function is invoked for which the component has no implemented logic. This allows software to detect that the operation exists in theory but is not available in the current implementation or configuration. In practice, applications and components propagate the status to callers, enabling graceful degradation or alternative handling.

The numeric value of STATUS_NOT_IMPLEMENTED is 0xC0000002. It is part of the NTSTATUS code family and is defined in header files used by Windows development environments (such as Ntstatus.h or WinNT.h). The code is distinct from other error statuses and should not be conflated with “not supported” or other failure conditions, which have different meanings and values.

In broader terms, the concept parallels ENOSYS in POSIX systems, where a function is not implemented by a given interface. STATUS_NOT_IMPLEMENTED thus conveys a precise lack of implementation within a specific component rather than a general or permanent incompatibility.