There are several ways to filter events with Event Log Explorer Viewer. You can query only specific events using XML queries, and the filtering will be performed by Windows Event Log Service on the target machine (before-load filter). You can also filter events when it loads events (on-load filter) and you can filter loaded events (after-load filter).
Before-load filter is applied on the target machine and reduces network load.
On-load filter is applied during event loading process - when Event Log Explorer receives events, but before saving the events into the internal storage.
After-load filer is applied to the events saved into the internal storage.
