Same problem. (Windows Vista, btw.)
Upgraded to Avast 5 and …blooey! No Internet Explorer, Firefox or Google Chrome. (Indicatively, I can receive and send emails–and, for all its limitations, still get on the web through Download Accelerator.)
Avast Support insists that Avast is not causing the problem–that it is my firewall settings which are causing it.
But I had not changed any firewall settings.
On a whim (and trusting Avast) I uninstalled my (Comodo) firewall altogether–and forked-out for Avast’s own Internet Security Suite: Antivirus and Firewall together. Surely they would not interfere with each other.
Not only was I wrong about that, but Avast now has a wad of my money.
Perhaps Avast can tell me, that if a firewall setting is the problem, then why–and right from a fresh installation–is Avast’s own Firewall interfering with its own Web Shield (which is the culprit here)???
Beyond that, I find firewall settings a complete mystery, so I tend to stick with the defaults. Accordingly, when Avast tells me to “allow” such and such in my firewall, perhaps they would be good enough to tell me just HOW to do that and not rely entirely on the Help files to explain it. Did I say "explain? I’ve just had my system out to TWO different computer specialists and, even though these were armed with Avast’s own explanatory emails, they have not been able to solve the problem. Having thrown their own hands up in disgust, the only thing they could do was to disable Avast’s Web Shield–leaving my system very vulnerable. I wonder, what did I pay for?
Avast: you keep telling me your product is not the problem. I, and TWO separate computer repair shops are telling you you ARE the problem–if only because even professionals cannot figure out how to configure Avast 5 “properly,” as you say it should be.
I’m telling you, Avast, you’d better get your stuff together and quick, or you’re going to loose one long-term customer–and I won’t go down quietly.
Oh, to hell with it.
I’m going over to AVG–and I’m going to demand Avast give me my money back.