NetWrix Active Directory Change Reporter is a free tool that reports the changes made to Active Directory and delivers a summary and detailed information on a daily basis. The report includes the 4 "W"s - Who, What, When, and Where - of all changes and includes "before" and "after" values for each setting. This report lists changes made to AD and Exchange configurations, mailboxes, AD schema, and many more. The tool is provided free of charge.