ecb1000, That looks like terrible experience! Would you mind to help us to solve it with a bit more details?
1) what did the Avast UI say when you'd found it wasn't working? Was there any message / error shown?
2) how did you Uninstall? A) from app menu > Uninstall Avast B) d'n'd of the Avast from Applications to Trash C) some other way?
3) lets check if there are any leftovers Avast AV installs - please open the Terminal and run following commands
- a) ls -la /Library/Application\ Support/Avast/
- b) ls -la /Applications/Avast.app/
- c) kextstat | grep avast
4) there should be some logs about Avast's install/uninstall process in the /tmp directory. Would you mind to send them to me - hasik (at) avast (dot) com
5) restart your Mac, it helps sometime. - but please check 4) first otherwise the /tmp will be cleaned on restart
