pszKey (PSZ) - input
The name of the key for which the profile data is returned.
The search on key name is always case-dependent.
If this parameter equals NULL, and if the pszApp parameter is not equal to NULL, this function enumerates all key names associated with the named application and returns the key names (not their values) as a list in the pBuffer parameter. Each key name is terminated with a NULL character and the last name is terminated with two successive NULL characters. In this instance, the ulLength parameter contains the total length of the list excluding the final NULL character.