Hi gmccann
Before you do that, Please download the following following program and use it to do a complete uninstall of Avast!.
http://freeweb.siol.net/razor256/downloads/avast_external_control.zip
This program is from one of our members (RejZoR) and is a Must Have Utility for Avast!
Once you’ve done the complete uninstall, then please re-install and I’m sure your problems will be over.
Good Luck and let us know how you make out.
Have a good evening.