On Windows, when you insert an USB or a CD/DVD into your computer, they are usually opened automatically. So the computer maybe infected autorun virus. To avoid that, you should turn off AutoPlay function.
Many websites support you watch online video/live TV on the Internet. If you want to play that videos by media player or want to embed them into your blog/website , you will need their stream URL. Now we have some methods to get online video stream URL.