When you uninstalled, did you use the Avast Uninstall Utility?
How to do an uninstall Avast and do a
CLEAN install:
1. Save a copy of newest version of Avast (5.0.677) for the version you need and save it to your HDD:
Pro –
http://www.avast.com/pro-antivirus#tab4AIS –
http://files.avast.com/iavs5x/setup_ais.exe2. 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 AIS and 5.0 Pro).
3. Disconnect from the Internet at this time.
4. Go to Control Panel and uninstall Avast through Add/Remove Programs if possible and reboot.
5. If Step 4 fails, boot into
Safe Mode (hit F8 repeatedly) and run the Avast Uninstall Tool.
You will need to uninstall BOTH AIS and 5.0 Pro.
6.
Reboot.
7. Install the newest version of Avast and
reboot.
8. Get Internet access and register your copy or add the license key for Pro, or AIS.
Let us know how this works for you. Thank you.