I help maintain a small computer network in a small office environment. We are running a mixture of windows xp/7pro pc 's. The internet is provided via a wireless provider and we are on a limited 1.5 Mbps connection. Some users are using the internet for things such as internet radio and if im not mistaken i had a couple of external user laptops connected to the network. Some don't recognize that their torrent programs are sucking up bandwidth as well as this internet radio. So in essence im wondering how to prevent external laptops from network use if this is a security risk and how to tighten up the network so users don't wastefully tie up internet resources. Email and internet web surfing are the primary uses for our company.