Splunk docs specify that you cannot monitor Windows event log (*.evt) files with a [monitor://] stanza as they are in binary format. The splunkd service monitors these binary files by using the appropriate APIs to read and index the data within the files. Not really sure if you can monitor the archived logs, but maybe try modifying the following stanza from the docs for the archived logs and see if it helps. Use the Full Name log property in Event Viewer to specify complex Event Log channel names properly
You can use the Full Name Event Log property in Event Viewer to ensure that you specify the correct Event Log channel in an inputs.conf stanza.
For example, to monitor the Task Scheduler application log, Microsoft-Windows-TaskScheduler-Operational, do the following steps:
Open Event Viewer.
Expand Applications and Services Logs > Microsoft > Windows > TaskScheduler.
Right-click Operational and select Properties.
In the dialog that appears, copy the text in the Full Name field.
Append this text into the WinEventLog:// stanza of inputs.conf as in the following example:
[WinEventLog://Microsoft-Windows-TaskScheduler/Operational]
disabled = 0 More information on the same: https://docs.splunk.com/Documentation/Splunk/9.0.3/Data/MonitorWindowseventlogdata
... View more