Need some help here - anyone?

I keep getting probs on my security history -

'Unauthorized access blocked (Access Process Data)

 

Actor: C:\WINDOWS\SYSTEM32\CONHOST.EXE

Actor PID: 3704

Target: C:\Program Files (x86)\Norton 30 Premier Edition\Engine 64\5.1.0.29\buVss.exe

Target PID: 4172

Action: Access Process Data

Reaction: Unauthorized access blocked. 

 

OK - THAT'S what the Advanced Details are telling me... 

and Norton tells me i've got no probs, don't need to worry about a thing. the problem IS - that i can FEEL someone in my computer - do you know what i mean?? when the keys don't work quite as they should, a bit sluggish, and screens don't load up the way they normally would on a 'clean' computer - i've had experience with trojan horses in the past when i had NO security - and so i know the 'feel' of when the computer's not running correctly.  Screens booting up strangely - something's just NOT right.... 

can anyone help me with this?? these are the only kind of alerts i'm getting in my history that are anything more than a tracking cookie - ANY SUGGESTIONS??? REALLY worried i'm going to lose another computer to the Blue Nowhere - and would REALLY like some help. cheers. 

Narnz.