cyberartist dumb question dept - ip filtering

Thanks 1337 - I have peer block uninstalled right now after a rebuild and had just wondered whether IP filter would do the trick system wide until I reinstall Peer Block. No worries. I know that if they wanted to get into my system that there's not much I can do about it - but I dont want to make it easy for anyone.
On the anti virus front - Ive used AVG and AVAST with varying degrees of success. At the moment (believe it or not) Im using Microsoft Security Essentials because I can get it legally now. (only piece of legal software I have is me operating system I think). MSE is quite good actually - Ive had no problems at all - and no virus down time either. I supplement it with Malwarebytes (free) and Super Anti Spyware (free) I have been running clean and smooth for a while this way. The rebuild was not because of virus attack - but simply because yours truly wasnt real happy with the last build. I am a fussy old bastard!
Your other tip is a good one too. I have used system mechanic from iolo for years - but it tends to be RAM hungry and wants to control everything. So I switched to the free version of Advanced System Care - but its a bit of a lightweight really - and short on features. So I checked out the link to Advanced System Optimizer that you gave me and it looks like the goods. I will DL it sometime tonight and take it out for a run.
Thanks again mate - your help and advice is always invaluable.