Well I personally use Norton 2006 and have 0 issues with VB6, VB.NET 2003, and VB.NET 2005.

My IIS works fine for ASP.NET apps and ASP.NET web services.

AVG gets touted as a good anti-virus, but recently I had a customers computer I was fixing and I installed AVG free, and while it did find a bunch of viruses and remove them. I then scanned the PC with Norton, and it found 70 files that were virus related. Now I know it didnt have 70 additional viruses on it, (although this machine was about as virus filled as I have ever seen) but norton did find some key files that AVG had missed.

Norton is quite the system hog, it uses more memory and CPU cycles than other AV products, but to date I have not had 1 virus infect my system (and believe me they have tried). This is usually peoples biggest complaint about Norton. However I run a dual core 3.6Ghz Pentium D with 2GB ram and raptor HDs so it really doesn't affect my systems performance.

So other than nortons rather large footprint, I think it is the best real-time protection, and it does not conflict with .NET at all.

Usually if anything, it is AV programs built in firewalls that cause problems with .NET

I would imagine (other than maybe some specific cases) any issues can be resolved by properly configuring access in the AV program for the processes assocaited with .NET

On a side node, NEVER.... EVER install ZoneAlarm. That is the worst firewall program EVER...

It caused my ASP.NET stuff to totally break down, I had no clue what was causing it because I had fully disabled zonealarm and shut it down, but the problem persisted.

Once I UNINSTALLED ZoneAlarm, things worked again.. yes I actually had to uninstall the software, even though it was not running and was totally disabled...