Abstract: A system for locating and monitoring electronic devices utilizing a security system that is secretly and transparently embedded within the software, firmware, or hardware of a computer. This security system causes the client computer to periodically and conditionally call a host system to report its serial number via an encoded series of dialed numbers. A host monitoring system receives calls from various clients and determines which calls to accept and which to reject. This determination is made by comparing the decoded client serial numbers with a predefined and updated list of numbers corresponding to reported stolen computers. Only calls from clients on the predefined list are accepted. The host also concurrently obtains the caller ID of the calling client to determine the physical location of the client computer.