I've removed avast free from two W10 PCs in the last few weeks and in both cases Windows Defender was greyed out and wouldn't activate.
After scanning the system drives for any files containing asw and deleting these files and rebooting, windows defender worked properly.
Regedit still shows some avast traces but I'm leaving those in place for now.
The instructions on how to deploy avastclear reflect that you have to start it from a regular session with admin privileges and then allow it to reboot into safe mode. Previous instructions told you to launch it in safe mode but this failed to work.
Files left behind after the most recent uninstall were two versions of aswsnx.sys and aswboot.txt
