HOW TO DELETE EVENT LOGS

NTFS Partition
Click the Start button, point to Settings, click Control Panel, and then double-click Services.
Select the EventLog service and click Startup. Change the Startup Type to Disabled, and then click OK. If you are unable to log on to the computer but can access the registry remotely, you can change the Startup value in the following registry key to 0x4:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog
Restart Windows.

NOTE: When the system starts up, several services may fail; a message informing the user to use Event Viewer to review errors may appear.
Rename or move the corrupt *.evt file from the following location:
%SystemRoot%\System32\Config
In Control Panel Services tool, re-enable the EventLog service by setting it back to the default of Automatic startup, or change the registry Startup value back to 0x2.
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FAT partition (Alternative method)
Boot to a MS-DOS prompt using a DOS bootable disk.
Rename or move the corrupt *.evt file from the following location:
%SystemRoot%\System32\Config
Remove the disk and restart Windows.
When Windows is restarted, the Event Log file will be recreated.