This morning I received a pop-up from Avast 4.8 informing me of update for 5.0 being available.
Clicking on pop-up ran the usual installation script. Installation failed - error in unpacking zip file. My system is Windows XP 32-bit.
After this occurred, I attempted to submit a problem report via your Contact Us on main page. But I was unable to as this appears to be available to registered users of the commercial versions of the software.
Upon comming to this forum, registering for forum access, then clicking on link provided in auto-gen email response, the web page at link caused: ashWebSv.exe: Unknown software exception.
Now I am using link on avast.com to download update and save as file. This appears to work.
Jim