NIS 2010: unauthorized user access logged and blocked

hi-im having a certain issue where i review my security history very often and see multiple times where it says unauthorized user logged-in acess- logged..risk medium..(acess process data)...and where at times it says they were blocked..(open process token) what does this mean??? and how can i stop this user from acessing my pc...(by the way im having a little issue where ther's a person trying to hack my pc.. what to do and does this certain norton product protect me 100% from these people?)

 

highly appreciated..frustrated 100%

 

<<Edit: Subject edited for clarity>>

Message Edited by TomV on 11-26-2009 10:58 PM