A user identifying system includes a user terminal and a server for communicating with the terminal. The terminal includes a detecting means that detects an event of a failure in accessing a service provided by the server, a recording means that records a timestamp indicating time of a failure in accessing the service when the event is detected, and a transmitting means that transmits, to the server, the timestamp and identification information allowing the server to identify the user of the terminal. The server includes a receiving means that receives the identification information and the timestamp transmitted from the transmitting means, and a specifying means that specifies a user identified by the identification information received by the receiving means when access by the terminal related to the timestamp has been made during an inaccessibility period wherein access to a service provided by the server has been unacceptable.