Disclosed are systems, methods and computer program products for reducing security risk in a computer network. The system includes an administration server that collect information about one or more computers in the network, including the following information: computer user's external drive usage history, software installation history, and Web browsing history. The server calculates based on the collected information a security rating of the computer user. The server then adjust a security rating of the computer user based on the security rating of at least one other user of another computer connected to the same computer network. The server then selects security policy of the security software based on the adjusted security rating of the computer user. Different security policies provide different network security settings and prohibitions on launching of executable files from external drives.