Easy and Free

http://www.devicelock.com/freeware.html

from the website:

"Active Ports - easy to use tool for Windows NT/2000/XP that enables you to monitor all open TCP and UDP ports on the local computer. Active Ports maps ports to the owning application so you can watch which process has opened which port. It also displays a local and remote IP address for each connection and allows you to terminate the owning process. Active Ports can help you to detect trojans and other malicious programs."

if you don't want to install anything- I like to install as little as possible
to keep registry and file bloat off my computer (uninstallers don't always remove everything...despite their misleading name)- open a dos shell and use netstat and start killing processes one by one.

Last edited by trollog; 05/16/08 05:48 PM.