What does this mean??? Event Log Scan

[Chance Orr <karismau () yahoo com>]

07/30/2003  23:49:02  612 Audit Policy Change Success audit Critical 
Security SYSTEM xxxxxxxxxx
07/30/2003  23:49:02  540 Successful Network Logon Success audit Critical 
Security ANONYMOUS LOGON xxxxxxxxxx
07/30/2003  23:49:24  680 Account Used for Logon Failure audit Critical 
Security SYSTEM xxxxxxxxxx
07/30/2003  23:49:24  529 LF: Bad user name/password Failure audit 
Critical Security SYSTEM xxxxxxxxxx
07/30/2003  23:49:33  680 Account Used for Logon Success audit Critical 
Security SYSTEM xxxxxxxxxx

This appears in my event log everytime I start my pc. I am using a 
firewall & XP-Home

thanx

---------------------------------------------------------------------------
----------------------------------------------------------------------------