1. A method for integrating a user computer with a badge system, said method comprising: a first user registering a first computer located at a site with a registration system; wherein said badge system controls physical access to said site; wherein in said registering step, a credential of said first user is authenticated, a first computer identifier of said first computer is determined, and said first computer identifier and a first user identifier of said user are communicated to said registration system; wherein said first computer identifier is one of computer identifier types, wherein said computer identifier types comprising: host name type, internet protocol address type, and media access control address type; enabling a wake-on-local area network mode on a firmware or a BIOS of said first computer; said first user badging-in at said site to said badge system; said badging system determining a second user identifier of said first user based on said badging-in step; said badging system updating a first presence status of said first user at said site, based on said badging-in step and said second user identifier; said badging system generating a badge-in event identifying said first user and said site; based on said badge-in event, said registration system determining one or more user computers located at said site, associated with said first user, and registered in said registering step; said registration system determining a first eligible subset of said one or more user computers that are not excluded by an administrator for wake-on-local area network; wherein said first computer is in said first eligible subset of said one or more user computers; said registration system identifying said first computer and said first computer identifier based on said eligible subset of said one or more user computers; determining a first media access control address for said first computer based on said first computer identifier; said registration system sending a wake-on-local-area-network signal packet tagged with said first media access control address to said first computer; said first computer booting up to operating system upon receiving said wake-on-local-area-network signal packet; said first user badging-out at said site using said badge system; said badging system determining said second user identifier of said first user based on said badging-out step; said badging system updating said first presence status of said first user at said site based on said badging-out step and said second user identifier; said badging system generating a badge-out event identifying said first user and said site; based on said badge-out event, said registration system determining said one or more user computers located at said site and a second eligible subset of said one or more user computers that are not excluded by said administrator for automatic badging-out process; wherein said first computer is in said second eligible subset of said one or more user computers; if said first user and said first computer are associated with a badge-out group, then determining one or more badge-out group rules associated with said badge-out group, determining presence statuses of group users belonging to said badge-out group using said badge system, and determining a change setting action for said first computer in response to said badge-out event based on said presence statuses of group users, said one or more badge-out group rules, and a group preference setting; wherein said group preference setting is preconfigured for said first computer; wherein said group preference setting is of a type of preference setting types, wherein said preference setting types comprising: shutdown type, hibernate type, logout type, sleep type, lock type, and no-action type; if said first user and said first computer are not associated with any badge-out group, determining said change setting action based on a user preference setting of said first user for said first computer; wherein said user preference setting is of a type of said preference setting types; said registration system sending a change setting signal to said first computer identifying said change setting action; and an agent in said first computer receiving said change setting signal and executing said change setting action.