Sometimes a background process running in Windows starts to consume a greater portion of the internet bandwidth and leaves nothing for the rest of the applications. Then when you try to open a website, it loads very slow or does not load at all. So how do you find if program or background process is consuming excessive bandwidth? You cannot do it probably using and in-built Windows tools, but you can use the SystemInternals’ TCPView tool to find out which program is pulling the most data from the internet as well as close its internet connection.
If you do not already have TCPView on your Windows PC, then you can download it from the Microsoft’s Technet website (the download link is given at the end of this article). The tool is a portable program and does not need to be installed. You can just extract it from the downloaded ZIP archive, launch it and agree to the EULA. It shows all the programs accessing the internet, the local and remote ports used, the downloaded and uploaded bytes, the remote IP address and more.
When you locate a program that you do not want to access the internet, you can right-click on it and select Close Connection from the context-menu. You can even kill the target process by selecting End Process from the right-click menu. You can also view the process properties from this interface.
But this does not prevent a process from re-opening another internet connection or relaunching itself (if you killed it). In order to permanently block the target process, you should note down its full path (right-click on it in TCPView and select Process Properties from the menu). Then you can follow the instructions as described in how to block a program in Windows Firewall to permanently block it from accessing the internet.
You can download the TCPView tool from http://download.sysinternals.com/files/TCPView.zip.