There is disclosed a computer entity having a trusted component which compiles an event log for events occurring on a computer platform. The event log contains event data of types which are pre-specified by a user by inputting details through a dialogue display generated by the trusted component. Items which can be monitored include data files, applications drivers and the like. The trusted component operates through a monitoring agent which may be launched onto the computer platform. The monitoring agent may be periodically interrogated to make sure that it is operating correctly and responding to interrogations by the trusted component.