I’m working on a C++ function to check if a registry path exists. It handles different root keys (like HKEY_LOCAL_MACHINE and HKEY_CURRENT_USER) and uses RegOpenKeyEx() to open the path.

The following is the function:

BOOL RegistryPathExists(const WCHAR* fullPath) {
    HKEY hKeyRoot;
    WCHAR keyPath[MAX_PATH];

    if (wcsncmp(fullPath, L"HKEY_LOCAL_MACHINE", 18) == 0) {
        hKeyRoot = HKEY_LOCAL_MACHINE;
        wcscpy_s(keyPath, fullPath + 19);
    } else if (wcsncmp(fullPath, L"HKEY_CURRENT_USER", 17) == 0) {
        hKeyRoot = HKEY_CURRENT_USER;
        wcscpy_s(keyPath, fullPath + 18);
    } else {
        return false;  // Unsupported root key
    }

    HKEY hKey;
    LONG result = RegOpenKeyEx(hKeyRoot, keyPath, 0, KEY_READ, &hKey);
    if (result == ERROR_SUCCESS) {
        RegCloseKey(hKey);
        return true;
    } else {
        return false;
    }
}

When I pass a path under HKEY_LOCAL_MACHINE, it works fine, but when I use HKEY_CURRENT_USER then it fails with error 0x12 (ERROR_NO_MORE_FILES).

Any idea why it works for HKEY_LOCAL_MACHINE but fails for HKEY_CURRENT_USER?

I’m trying to open HKEY_CURRENT_USERSOFTWARETESTVALUEand HKEY_LOCAL_MACHINESOFTWARETESTVALUE, and I’ve confirmed that the user account has the necessary permissions to read them by checking the registry.