_RegQueryValueEx

include vmm.h

LONG _RegQueryValueEx(HKEY hkey, LPTSTR lpszValueName, 
    LPDWORD lpdwReserved, LPDWORD lpdwType, LPBYTE lpbData, 
    LPDWORD lpcbData)
 

Retrieves the type and data for a specified value name associated with an open registry key. See the documentation for the Win32 function of the same name for additional information.

• Returns ERROR_SUCCESS if the function succeeds. Otherwise, an error code is returned, possibly one of the following:

hkey

Handle of an open key or one of the predefined keys:

HKEY_CLASSES_ROOT

HKEY_CURRENT_USER

HKEY_LOCAL_MACHINE

HKEY_USERS

HKEY_CURRENT_CONFIG

HKEY_DYN_DATA

lpszValueName

Points to a null-terminated string containing the name of the value to be queried.

lpdwReserved

Reserved; must be NULL.

lpdwType

Address of variable that receives the type code for the value entry. This parameter can be NULL if the type is not required. The type can be any value or one of the standard values:

REG_BINARY	Binary data in any form.
REG_SZ	A null-terminated UNICODE or ANSI string.

lpbData

Address of buffer that receives the data for the value entry. This parameter can be NULL if the data is not required.

lpcbData

Address of variable that specifies size, in bytes, of the buffer addressed by lpbData.

Of the predefined key values, only HKEY_LOCAL_MACHINE and HKEY_DYN_DATA are available to VxDs during initialization time. The entire registry space can only be accessed after VxD initialization is complete.