A software monitoring and auditing system which determines the inventory of software products on a computer includes data reducer software which processes detailed software usage data gathered by a monitoring component of the software to create a condensed usage database. The reducer software contemporaneously converts the data records in a manner which reduces the amount of data records by at least a factor of 100, consuming less computer memory and allowing users of the software monitoring and auditing system to review usage data on a desktop PC or the like.