The DRV_ENABLE message causes a Windows NT user-mode multimedia driver to just return a nonzero value (see Comments section below).
Parameters
dwDriverID
Driver instance identifier. This value is zero for the DRV_ENABLE message.
hDriver
Driver handle.
uMsg
DRV_ENABLE
lParam1
Not used. Set to zero.
lParam2
Not used. Set to zero.
Return Value
The driver should return a nonzero value.
Comments
The DRV_ENABLE message is one of the standard driver messages. A client sends the message by calling the driver’s DriverProc entry point, passing the specified parameter values.
Windows 95 drivers respond to the DRV_ENABLE message by enabling hardware. Because hardware access under Windows NT is controlled by kernel-mode drivers, Windows NT user-mode drivers do not perform any operations when they receive a DRV_ENABLE message.