NoteHKLM\SYSTEM\CurrentControlSet\Services\EventLog\<Log-name>\
The <Source-name> subkey is a variable representing the EventLog\<Log-name> subkeys that store entries for a log source. A log source is a program, service, or operating system component that writes to an event log.
This subkey doesn't actually appear in the registry. This variable subkey displays the entries and subkeys that are common to many of the source-specific subkeys in the EventLog subkey.
Each <Source-name> subkey represents a program or service that writes to the log represented by the <log-name> subkey. The <Source-name> subkey stores configuration data that tells the Event Log service where to find and how to display the events for that source.
For example, the Dr. Watson for Windows 2000 service records its events in the Application Log in Event Viewer. Therefore, the source, DrWatson, has a subkey in the EventLog\Application subkey.
Note
If a source program that is not represented by a <Source-name> subkey writes an event to an event log, the Event Viewer uses the entries in the subkey identified by the value of PrimaryModule to display the event in Event Viewer.
Caution
Do not change the values of these entries by editing the registry. Source programs should use the standard Win32 APIs to register a source program and write events to the event log.