Vista - Unknown Internet connection access.

I’m not sure if this is the correct thread for this, if it isn’t, please let
me know what thread this should be posted in.

Problem;
Every 30 seconds (exactly), something is accessing the internet connection
(broadband cable).
I can see this, using the Windows Task Manager (networking window).
Normally, this would not be a problem, but every time this access occurs, it
completely disrupts online game play, for the duration of the access (about
one second each time).

Is there a tool that I can use to see, in real time, what programs are
accessing the internet connection?
Or, maybe you already know what is causing this and how to correct it?