BFIdleTracker is part of the BigFix Power Management site and its job is to record how long it has been since the current user was idle (keyboard or mouse input). You need to deploy it through the power management site and it writes it results to the registry… Probably the easiest thing to do will be to look at the “User Idle Tracking” analysis in the Power Management Fixlet site and you can use the same techniques it uses to track user idle time for your custom needs.