If the log file has been configured not to exceed 2MB - 64K, an application can expect the EVENTLOG_SEEK_READ flag to work properly without any problem. To configure the log file size, use Event Viewer and select the Log Settings menu item from the Log Menu.
If the log file is 2MB or larger, the seek method of reading the event log will fail to read the earlier records in the file. For example, expect ReadEventLog to fail when reading records with the dwRecordOffset parameter set to 1 or 2 or maybe 11 or 12, depending on how full the log file is. ReadEventLog may continue to succeed and work properly for seeking to later records, for example dwRecordOffset set to 100 or 200.
The problem with ReadEventLog using the EVENTLOG_SEEK_READ flag is related to the file size and not the number of records.
Platform SDK: Windows Base Services; Debugging and Error Handling; Event Logging; Event Logging Reference
Article ID: 177199 - Last Review: Nov 21, 2006 - Revision: 1