Then try a new clean install, safesurf have made nice userguide here
quote:
I suggest an uninstall of Avast and CLEAN install[/b] to fix your problems.
1. Save a copy of newest version of Avast (5.0.594) for the version you need and save it to your HDD:
Free –
http://files.avast.com/iavs5x/setup_av_free.exe Pro –
http://files.avast.com/iavs5x/setup_av_pro.exeAIS –
http://files.avast.com/iavs5x/setup_ais.exe 2. Download the Avast Uninstall Utility, aswClear5.exe
http://www.avast.com/uninstall-utility and save it to your HDD (it has uninstall tools for both 4.0 and 5.0).
3. Disconnect from the Internet at this time.
4. Uninstall Avast through "Add/Remove Programs".
5. Boot into Safe Mode and run the Avast Uninstall Tool.
6. Reboot twice.
7. Clean your computer up (clean up cache, etc.).
8. Install the newest version of Avast and reboot twice.
9. Get Internet access and update Avast definitions.
10. Register your copy or add the license key for Free, Pro or AIS.
11. Reset your settings, if needed.