1. Right-click 'My Computer,' and then click 'Manage.' Double-click 'Services and Applications,' and then click 'Services.' In the right pane, right-click 'Windows Event Viewer,' and then click 'Stop.' This disables the Event Viewer service.
2. Restart your computer.

3. Search for the log file you want to fix (Application.evt, Security.evt, or System.evt), in your Windows folder, and then rename it to [filename].old.
4. Right-click 'My Computer,' and then click 'Manage.' Double-click 'Services and Applications,' and then click 'Services.' In the right pane, right-click 'Windows Event Viewer,' and then click 'Start.' This enables the Event Viewer service and creates a new log file.
5. Restart your computer. Event Viewer will begin to log events in the new log file.