Ok, now THAT was REALLY Embarrassing! :o)

Given that I NOW check for <> 0 (SILLY ME) instead of .T. it is NOW not throwing an error, but it IS returning 0 no matter how I seem to set m.lcDeviceInterfaceData beforehand:

m.lcDeviceInterfaceData = Padr(BinToC(28, [4RS]), 4, Chr(0)) + Replicate(Chr(0), 24)
m.lcDeviceInterfaceData = CHR(32)+CHR(0)+CHR(0)+CHR(0)
m.lcDeviceInterfaceData = long2str(32)+REPLICATE(CHR(0),28)
m.lcDeviceInterfaceData = num2dword(32)+num2dword(0)+num2dword(0)+num2dword(0)+num2dword(0)

Yet, I am sure the other parameters I pass are all good. Can you easily determine what is wrong with the manner(s) in which I attempted to set m.lcDeviceInterfaceData? None of the above return anything other than 0 so I am missing something obvious is setting m.lcDeviceInterfaceData...


And this works:

	m.lnRetVal = SetupDiEnumDeviceInfo( ;
		m.lnDeviceInfoSet, ;
		m.lnx, ;
		@m.lcDeviceInfoData)

but I cannot get a result <> 0 from SetupDiEnumDeviceInterfaces()


By the way, I should have caught that immediately:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/devio/base/setupdienumdeviceinterfaces.asp
Return Values
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.