|If you would post your NETSTAT -B we can see if you have a Zombie Bot on your computer or something that is using your bandwidth. You could just do this...|
NETSTAT -B > C:\NETSTATLOG.TXT
Then open the netstatlog.txt on your C:\ in notepad, copy the contents and paste it. Thanks. You could also go through the LOG and use the WhoIS web site to determine who each of the internet connections are connecting to.
If you see a connection with someone you don't know then look at the service or program that was opening the connection, in the NETSTAT log. Google the app or service to see what uses it. If it is an app that is a high risk or one you did not install on your system then Google for how to uninstall it.
I also like the Wireshark Idea posted above because you can see what connection is doing the most packets. Then with the NETSTAT log, identify what service or app is doing that connection and remove it.
This kinda advanced stuff so be careful not to remove the wrong app or service or you might break your computer. If you are not comfortable with doing this, then take it to some one who is. As with any thing at this level, I would do a System State backup before you begin.