Thank you for your time and assistance in advance. About a month ago and after either a TB or a Windows 10 update the problems started: All custom settings - including my 18 different email accounts, their passwords, all options settings I've changed, even the location and size of the TB window, etc - were erased on exiting TB or restarting the computer. I've searched the web, found several recommendations, deleted the Key3 .db and other files recommended, reentered all account info, passwords, etc, etc - many times over and over and nothing worked. I do use CCleaner and I do have the TBird program directory as well as the Profile directory excluded. On 9/7/19 I updated to the 60.9.0 (32 bit) version and only one thing changed: TB now retains all my 18 account names - but nothing else: On exiting the program all my other settings and passwords are again erased. I tracked down which files in the Profile directory change after exiting the program: some of these simply disappear and some just change their contents: \cookies.sqlite-shm \cookies.sqlite-wal \downloads.json \extensions.json \favicons.sqlite-shm \favicons.sqlite-wal \logins.json \places.sqlite-shm \places.sqlite-wal \session.json \sessionCheckpoints.json \webappsstore.sqlite-shm \webappsstore.sqlite-wal \xulstore.json I am now out of ideas and would be grateful for some help to fix this. Thank you again.