as a tech for 23 years. with a 100% fix rating. Nortons IS the best hands down.
To unistall Avast go to safe mode.
If you have the folder still there you sh old see in side of it a SETUP exe. OR wise unistall exe.
If so .. go to SAFE MODE then add remove. The issue your having is becasue the program can NOT be reomoved while running. In regular mode it has been running. Not to mention FREE antivirus software is always a pain to get rid of. Producing false positives and fake alersts. Even Avast does this. This is why it is hard to remove as it is alwas communicating.
And yes alot of haters for nortons as in the 908's early 2000 era Nortons on friday nights would kik in and LAG the hell out of a system. Doesnt happen anymore hanst for a few years now. Norotns has the Largest data base for antiviral fixes and the For telling in virus activity. Just a tech for a long time and I found many antivirus that were just as much as a threat as the things it is suppose to protect you form, mainly Uninstalling one of the FREE versions.
Try it all in safe mode. Downloading a Uninstaller is honestly not the answer, as 3rd party programs are installed as you try to install IT to get rid of something .. giving you something else to worry about. Its kinda like in stalling a Driver
finder to fix a driver issue. IF you have some how Delted avast folder, you will need to manually clear your registry. ( Which can be done in safe mode aswell) but again a registry cleaner is going to install "other" as it does its job. I highly recommend seeing your Tech. No matter hw "good with coputers" you may be or your frined, see your educated licnsed A+ ASCII certified tech. he can fix it without formatting.