RETERR DiOpenClassRegKey(LPHKEY lphk, LPCSTR lpszClassName)
Open the class registry key, and optionally a specific class's subkey.
lphk
Buffer to receive the opened registry key.
lpszClassName
The name of a specific class. If non NULL the specificed class's subkey will be opened are retured if it exists. If this parameter is NULL, the registry key of the class branch (HKLM\System\CurrentControlSet\Services\Class) will be returned.