I guess you could enumerate the active drivers in HKLM/Drivers/Active
looking for one that you like for WiFi. WiFi is not a global thing. You
could have two dozen WiFi adapters on some device, so there's no
IsWiFiActive() call. Why do you care? Generally, applications should
ignore the transport mechanism and just make a connection to the network and
use it, ignoring the media being used to do that...
Paul T.