loading snort 1.9.0

["jbaird" <jbaird () tele-tector com>]

I attempted to load vrer 1.9.0 for the first time yesterday. When I executed it, the wpcap.dll file was missing. Where 
can I find this file? Also what is a .tar.tar file and why does my system see it as a zip file? Please help!!!

John W. Baird Jr.
Program Manager
Tele-Tector of Maryland
443-604-5897
jbaird () tele-tector com