WNF updates are kernel-pushed. Polling a registry key or waiting for a broadcast message is slow and wasteful. NtQueryWnfStateData reads the current state directly from the kernel’s WNF database.
NtQueryWnfStateData can return STATUS_NOT_FOUND, STATUS_INVALID_HANDLE, or STATUS_ACCESS_DENIED. Your code must treat these as normal conditions, not crashes. ntquerywnfstatedata ntdlldll better
Monitor session switch and user presence states to lock/unlock automation features. WNF updates are kernel-pushed
Many WNF state names (e.g., WNF_SHELL_ACTION_CENTER_PRESENCE, WNF_GAME_EXPLORER_MODE) are not exposed via any public API. By using NtQueryWnfStateData with the correct state handles (discoverable via brute-forcing or analysis of shell32.dll, wmp.dll, etc.), you can monitor internal system flags that no documented API provides. If you try to call it from your
You won’t find Microsoft documentation for NtQueryWnfStateData. It’s not for you. It’s for:
If you try to call it from your own app, you’ll likely get STATUS_ACCESS_DENIED or STATUS_NOT_IMPLEMENTED, because WNF state names are protected by security descriptors in the kernel.