At times you may have only a single website open and yet you may find your Modem’s light flickering actively, indicating steady a data transfer. Apart from your browser, silently, there are several programs which may be accessing the internet from your Windows PC without your knowledge.
To find out which programs are accessing the internet, download and use TCPEye, a freeware!
TCPEye is network monitoring software that displays the list of all currently opened TCP/IP and UDP ports on your local computer.
For each port in the list, information about the process that opened the port is also displayed, including the process name, full path of the process, version information of the process (product name, file description, and so on), the time that the process was created, and the user that created it, Country Name + Flag.
In addition, TCPEye allows you to close unwanted TCP connections, kill the process that opened the ports, and save the TCP/UDP ports information to HTML file , XML file, or to tab-delimited text file and also get it checked for malware.
TCPEye also automatically mark with pink color suspicious TCP/UDP ports owned by unidentified applications.
You might to also check out these Free Bandwidth Monitoring Tools for Windows 7.