You probably need to do a clean install...
Download and save the avast uninstall tool
Download and save your choice...FreeProAvast Internet SecurityPremier
Run the uninstaller from above. You will be directed to reboot into safe mode...click "yes".
Install choice from above. Use the "custom" install. You may need to either de-select the "browser protection" or disable the "avast online security" add-on in your browser(s).
Reboot and either register or insert license.
Dell Inspiron, Win7x64 SP1, Pentium Dual-Core T4500, 6 GB Ram, Avast Free v2015.10.2.2214, Comodo Firewall 5.12 w/D+, MalwareBytes Premium 2.0, MCShield, Super Anti-Spyware Free, SpywareBlaster, OpenDNS Premium, Keyscrambler Personal, Ghostery. CCleaner, Greenshot, Firefox (latest build), Google Chrome (latest build) and, various browser security tools.
When you do something, do it with a purpose and do it on purpose.