By default, guests and unauthorized users can read the System and Application
event logs (not the Security log). To restrict to authenicated users:
Hive: HKEY_LOCAL_MACHINE
Key: SYSTEM\CurrentControlSet\Services\EventLog\Application
Name:
RestrictGuestAccess
Type: REG_DWORD
Value: 1 Restrict access to Application log
Hive: HKEY_LOCAL_MACHINE
Key: SYSTEM\CurrentControlSet\Services\EventLog\System
Name:
RestrictGuestAccess
Type: REG_DWORD
Value: 1 Restrict access to System log
Frank Heyne has made available a Windows NT
Eventlog FAQ .