Hi,
Relative new user here, I've been using Avast for a few days now and like it very much, I did have some issues with my news and email readers but reading through the forums here solved those issues :-)
I have updated avast to the 5.0.677 version tonight and after a reboot I had no internet or lan connections, I removed avast, reinstalled but to no avail. I then had a look at online armor that I run, darn thing looked ok but deactivating the fire wall allowed lan and internet access, looking through online armors rules I noticed that Avastsvc.exe was blocked, it wasn't before I updated avast so I removed avast and reinstalled, updated and the same thing happened ! I changed the firewall rule to allow and all is well, no problems :-) So if anyone used online armor and updates avast and looses connection, have a look at the firewall rules first before trying anything, it may be a one off thing with my PC but I thought I would post here just in case.
Mart.