HMODULE hNtdll = LoadLibraryA("ntdll.dll"); if (!hNtdll) // Handle error

: Allocate the buffer based on that size and call the function again to retrieve the actual data. Why It Is "Better" Than Alternatives Registration-less : Unlike older Windows notification methods (like WM_DEVICECHANGE

Many WNF state changes are already exposed through official APIs. Instead of querying the raw WNF state:

In the hidden depths of the Windows operating system lies a powerful, yet largely undocumented, mechanism for state notification and data retrieval: (Windows Notification Facility). At the heart of interacting with this system is a function exported from ntdll.dll — NtQueryWnfStateData . For decades, developers have relied on higher-level APIs like RegisterWaitForSingleObject or WMI queries to monitor system state changes. But to achieve better performance, lower latency, and access to kernel-level state data, you must descend to the native API layer.

typedef NTSTATUS (NTAPI *pNtOpenWnfState)(PHANDLE, ACCESS_MASK, PVOID); typedef NTSTATUS (NTAPI *pNtQueryWnfStateData)(HANDLE, PVOID, ULONG, PVOID, ULONG, PULONG);