i recommend if u have the time, cause its going to be lengthy
1. Download a fresh Avast! 7 package from
http://www.avast.com/free-antivirus-download (to reduce chance of corrupted install)
2. uninstalling Avast! the normal way with windows
3. run Avast! uninstall utility
http://www.avast.com/uninstall-utility (please do it in SAFE MODE! )
4. run the uninstall utility (4 TIMES) total, one for Avast! 7
5. reboot and go into safe mode again, 2nd time for Avast! 6, 3rd Avast! 5, 4th Avast! 4 (this is because u do not know which version u updated from, thus the need to thoroughly clear all remnants of Avast! from each version).
NOTE: each time u run the uninstall utility for each version, u need to restart and go into safe mode again!
6. reboot again, this time to normal windows mode
7. install the fresh package
if this still fails to solve ur problems, please generate the general support package for Avast! team to look into.
see the screenshot.