Note: Uthernet (TFE) support in Applewin was made possible by implementing the GPL source written by Spiro Trikaliotis for the Vice emulator - http://www.viceteam.org/
To enable Ethernet support in AppleWin you must first download and install WinPcap.
An Alternative to downloading WinPcap is to get the Ethereal package which includes WinPcap along with Ethereal network analyzer code. To use Ethereal to capture traffic (other then your own) you must be plugged into a shared hub vs a switch. If you plan on doing any network programming ethereal is a definite must have.
If you have more then one interface you may need to select them in turn in order to get the text description for each interface vs what WinPcap likes to use for a reference. Select Ok. and then close AppleWin. *Note:* Wireless does not work with WinPcap.
Grab the 80 Col. Primary Disk and Supplementary Disk images if using Apple //e emulation or the 40 Col versions if running Apple II+ emulation. You should also grab a copy of the Uthernet/Contiki getting started guide http://www.a2retrosystems.com/a2UtherManual.pdf
Choose Directory Application and then select configuration edit program. Tab down to the Slot param and change it to '3'. The emulation only works in slot 3.
If you have ZoneAlarm running then try disabling it inorder to access the web.
if you are still having difficulty then you should refer to the VICE network support page for additional information - http://vicekb.trikaliotis.net/13-005.shtml