We have a server with windows server 2003 sp 2 configured on it.
We are observing from quiet a while that it doesn't log events for about 2-4 hours, this happens quiet frequently everyday.
We have recently reinstalled operating system on the server, this problem was before re installation of windows and it still persist after the re installation.
First ensure that your evt/evtx file is not corrupted because it might be the issue behind it
Aslo the link posted by pankaj is useful for your query also you can Lepide's Event Log Manager to collect network wide events
If ELM is collecting events from remote computers without using agents is it necessary to open TCP port(s) or change other settings on the remote computers so ELM is able to access their event logs?