The driver's initialization routine (the entry point for the DLL) should check
to make sure that the appropriate network is actually installed and running. If it
is not, the routine should return zero to prevent the driver from being loaded. Windows then behaves exactly as if no network driver were installed.
The driver should also check the netwarn setting in the [Windows] section of the WIN.INI file. If the value is 1, the driver should display a message box to inform the user that the network is not installed before returning to Windows. The netwarn setting allows users who run Windows frequently without loading the network to disable the message box.