You can actually check if they still are connected to your PC, with a little use of command prompt.¨
First of all you have to close all programs that uses an internet connection (There will still be some programs running, such as firewall etc. but it doesn't matter)
Go to start, and in the search box type: Cmd and hit enter.
Type in: Netstat -ano
You will see a list of IP adresses, and next to that you will see if its "LISTENING" or "ESTABLISHED"
"ESTABLISHED", means that, some program is connected to your computer by the internet.
Next to ESTABLISHED, you see a column called "PID", and then you see the program has a number.
Now open your taskmanager: (Hold CTRL + SHIFT + ESC). now head to "Processes" and press "View" > "Select columns" and choose PID (Process Identifier). Now you will be able to see the PID Number.
In the command prompt you check the PID number, and in your Taskmanager you close the process with the PID number that was shown in Command Prompt.
* AND ALSO! before you close process you got a mistake to, right click and press "Open file location", then you can remove the unwanted program, because maybe its a program that opens with windows, so close process won't always be enough.
Best Regards,
Zmokamok