ERROR_HOOK_NOT_INSTALLED - 1431 (0x597)
The hook procedure is not installed.
Updated: Feb 21, 2026
Technical Meaning
The error code ERROR_HOOK_NOT_INSTALLED with the numeric value 1431 and hexadecimal representation 0x597 indicates that a required hook procedure is missing or not installed in the system.
Error Details
A hook procedure is a function that can be inserted into the message processing of an application. When a specific event occurs, such as a keystroke or window creation, the operating system calls the hook procedure to perform additional actions before passing control back to the original application.
When this error is encountered, it suggests that the necessary hook procedure was expected but not found. This can occur in various scenarios where hooks are used for monitoring or modifying system behavior.
Usage Context
This error typically occurs within the Windows API environment when a function expects a specific hook to be installed and active. It may appear during application development, debugging, or certain system operations that rely on hook procedures.
Developer Interpretation
Developers should interpret this error as an indication that a required hook is missing in their code or configuration. This could mean that the developer has not registered the necessary hook procedure, or there might be issues with the registration process.
Related Errors
ERROR_HOOK_NOT_ENABLED(1430, 0x596): The hook is enabled but not installed.ERROR_INVALID_HOOK_HANDLE(1287, 0x507): An invalid handle to a hook procedure was specified.
FAQ
Q: What does the error code 1431 mean?
A: It indicates that a required hook procedure is not installed in the system.
Q: How can I resolve this issue?
A: Ensure that all necessary hooks are correctly registered and active. Check your application's configuration and ensure that any required hooks are properly implemented.
Summary
The ERROR_HOOK_NOT_INSTALLED error code (1431, 0x597) is a specific technical indication that a hook procedure expected by the system or API is missing. Developers should verify their implementation of hook procedures to resolve this issue.