southern writes:  

What process in your machine is causing network traffic, and how much?
Network Traffic Monitor shows you which processes in your machine are causing TCP/IP network traffic, how much traffic that is, and over which IP ports this traffic takes place. For each process it can show detailed information, including the path to the process executable. Network Traffic Monitor can give you a historic overview of the network traffic since the application was started, and save that info to a file for later examination.
Network Traffic Monitor is freeware. You may copy and distribute it as long as you don't make money from it and distribute it in its entirety, including the accompanying README.TXT file. You can download from the download page.

:: Program details, requirements and limitations
Requirements:
Network Traffic Monitor can only be used on a machine running Windows XP (Home or Pro) or Windows Server 2003.
nicocuppen