tronyx@wrekx:~/Desktop$ sudo dpkg -i NessusClient-3.0.0-debian3_i386.deb
(Reading database ... 149723 files and directories currently installed.)
Preparing to replace nessusclient 3.0.0 (using NessusClient-3.0.0-debian3_i386.deb) ...
Unpacking replacement nessusclient ...
Setting up nessusclient (3.0.0) ...

tronyx@wrekx:~/Desktop$ sudo dpkg -L NessusClient-3.0.0-debian3_i386.deb 
Package `nessusclient-3.0.0-debian3_i386.deb' is not installed.
Use dpkg --info (= dpkg-deb --info) to examine archive files,
and dpkg --contents (= dpkg-deb --contents) to list their contents.