How to disable wifi adapter programmatically

I'm trying to enable and disable the internal wifi adapters in PPC 2003. I
have an ipaq 5555 and a Dell Axim (X3 I think), and the ipaq does it fine but
the Axim doesn't. Here's the code I'm using:

NDIS_DEVICE_POWER_STATE power = NdisDeviceStateD3;
return DeviceSet(OID_PNP_SET_POWER, &power, sizeof(power));
The DeviceSet method calls a tool which sends the OID to the adapter.

Both units claim to support this OID, but only the ipaq actually turns the
power off on the wifi adapter, the Axim returns success (drivers are told to
do this even if they don't do anything) but leaves the power.

So I'm assuming this isn't the way to do it in the general case. It seems
that there should be some kind of device manager api I can use - I tried
using the setupDI routines but I was unable to link properly (I also have an
ftp control in my code but I can lose that if need be, all of the socket
functions were unresolved when I included setupapi.lib). Does anyone know
how to do this in the general case?

Thanks for any help on this and have a great 2005.
Red