Windows 7 – How do I troubleshoot my Internet traffic?

I’m running Windows 7. Is there a way for me to see which currently running programs communicate via the Internet (either sending or receiving data) and how much data they are transferring?

Solution:

Or WireShark:

Wireshark is the world’s foremost network protocol analyzer. It lets you capture and interactively browse the traffic running on a computer network. It is the de facto (and often de jure) standard across many industries and educational institutions.