Until recently I was using The Proxomitron proxy server which blocked a HUGE amount of pop ups, ads and other crud....but my WinXP didn't like it when it tried to access protected areas of memory. Oh well.
I forgot to mention that I use ZoneAlarm (free) for a firewall. I had used Sygate in the past but liked ZA a little bit better.
I have not been a victim of any NAV problems (yet) so I'm still using it. It's done the job so far.
I actually had good performance from the first NAV I used...version 2000 I think. When my paid subscription ran out I upgraded to Norton System Works and that's when the real fun began.
NSW was such a resource hog and so intrusive to my other computing needs that I started looking for an alternative.
On an FR thread I found a link to the AVG Free Anti Virus webpage and downloaded it. I was a little dubious at first so I started researching it before installing.
The straw that broke the camel's back was when Symantec (Norton's parent Co.) bought the company that manufactured the router I use for my home LAN. I had a need for customer support and their response was less than acceptable. It bordered on apethetic.
So I bought a different brand router and sent the other one to them in pieces...along with a letter to explain my displeasure and my intention to never buy or use a Symantec product again.
I installed that AVG and also the Outpost firewall software that I also found a link to on FR and have never regretted it...nor been asked to pay a dime for it.