No Windows version places a limit to the size of the Event Log. 512 KB is just the default value of the (default) "Limit to ..." option.
Just have your customers change this value to a higher one, or tell them to clear their Event log. Something tells me they already have intermittent problems with other applications due to the full event log.
Besides, trying to do something to a user's system without leaving a trace in the Event log can be seen as an attempt to hack the system by some tools and admins ....