Which is the best?

Petey7 said:

The best option by far is to not use the internet. It will keep 99% of infections from reaching your computer and remove the need for a firewall entirely.

thats no fun

A hypothetical question: If one turns UAC to highest level and changes the setting to ask for credentials at prompt, is there any need for any AV at all? Surely nothing can get installed / changed without you specifically allowing it with your admin password?

I ask this because usually I always ran as limited user in XP and this has saved me on a couple of occasions, even though AVG slipped up. While I switched to Avast since last couple of years (I have been quite happy with it) I am impressed by Windows 7 security in general and running as standard user or even as Admin with UAC at highest with credentials, should prevent any issues and probably obviate the need for an AV.

Any AV does place huge drain on system resources. Just disconnect from Internet and see the difference between a fresh install and one with only any AV installed.

I have my UAC set to standard, I think...
I suppose if you were going to use your computer but did not intend to connect to the internet then you wouldn't need an AV product. But Windows would more than likely keep yelling at you because you would not be protected.
But I do agree that almost every AV has some kind of system slowdown, even if it's a bad product that doesn't do its job!

I think that my point is being missed. Since windows 7 has system similar to Linux - asking for admin user/password for any important system setting change / program installation - then once I set UAC to highest level and ask for password, how is it possible for any virus, malware, trojan, rootkit or other malicious program to install itself? If it is not possible, then why is AV necessary?

I am not that familiar with what UAC can do. I would assume that malware could still pass through it even if it is set to the highlest level possible - but I'm not sure.

I believe that enhanced UAC should do the job. Even the latest .lnk vulnerability, MS has stated that a mitigating factor is running as standard / limited user.