Thanks for the responses. Just for clarity - I have a Desktop pc - no laptop.
1. When you say Wi-fi I am assuming you mean 'wireless' ? - I connect to the internet with a modem - cables are plugged into my pc and into the modem. So does that mean that no one can use my internet connection? That would be a relief.
2. I can use the terminal to enter command lines - if I copy and paste them. :}
3. I do use bit-torrent - and recently - did so quite a bit. So I am assuming that because I had been using it a number of connections were opened - which would account for what happened possibly? But when i close down bit torrent it says that it's shutting down the connections?
4. I checked my security at the link given - I do not understand the result.
"If the machine name shown above is only a version of the IP address, then there is less cause for concern because the name will change as, when, and if your Internet IP changes. But if the machine name is a fixed account ID assigned by your ISP, as is often the case, then it will follow you and not change when your IP address does change. It can be used to persistently identify you as long as you use this ISP." I am registered with a reputable ISP Provider. I do not know if my 'machine name' is fixed or not - I have reloaded the page a few times and the name remains the same.
5. I don't want to change passwords unless I have to - should I change them every now and then?
6. Sorry - re: the bluetooth appy i said I removed - I thought that perhaps if someone has bluetooth - eg: someone in my area - that they could perhaps use my internet connection from a laptop and cell phone. Or is that just a bad understanding on my part?