Hi,
quite the same problem for me with windows Vista Family Edition Premium. I use Avast "free" for many years. Upgrade didn't work (i had the notification avast didn't completely protect, i made "solve" and it completely block access to internet. Then it completely freeze my computer, no way to stop the avast task. After checkdisk...i downloaded aswclear, and then properly reinstall. impossible for install to finish, it stops on the last exe file. Freeze again, restart. ""Failed to load language dll [1033\UILangRes.dll]"" at the login.
CC Cleaner because uninstall didn't work properly
Redownload the file on avast server, re-install, doesn't work...
It's the first time i have such complains with avast, i clearly think to switch for a competitor...really the worst version to my mind and impossible to download the old one 8.01.1497: despite correct name, all links go to the new version...