This KB article describes various security-related and auditing-related events in Windows 7 and in Windows Server 2008 R2. This article also provides information about how to interpret these events.

All these events appear in the Security log and are logged with a source of Security-Auditing. This article also describes how to retrieve more descriptive data about individual events.

KB977519 lists all Windows 7 and Windows Server 2008 R2 security audit-related events by category and by subcategory.

Quite useful for troubleshooting!