Does the shortcut you click to launch TB have -p after ...\thunderbird.exe in its Properties?

Unfortunately no. There are no options in the target string. I am on windows 10 and right clicking START and entering the full starting string ( C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe) produces the same effect, i.e. " Choose User profile " window comes up. I don't understand why putting changes into the choose windows profile window like clicking on the " Use selected profile without asking on startup" are not saved for the next time Mozilla thunderbird is started. It is as if the changes are being made but to another file or a file in a different location.

What's the value of profile.manage_only_at_launch in Config. editor? The default is false.

http://kb.mozillazine.org/About:config_entries#Profile.

Check this preference in each profile.

Thank you for your reply. I found the config editor in a slightly different place but the setting ( profile.manage_only_at_launch) was false so that was disappointing . Options > config editor ( in a small box after scrolling all the way to the end ) was where I found the config editor not under tools as per the wiki article.

Can you suggest what might be causing my problem . It is strange as my wife, under her sign on does not have the problem . Thunderbird starts without showing the profile selection window.

Regards, Andrew

Did you check all profiles for the preference? It's possible that if just one of them has the value 'true', the profile manager is displayed on startup. You have to be careful renaming profile folders, doing it not in File Explorer but with Profile Manager.

Bearing in mind your warning about deleting/editing profile folders in File Explorer, I found my way into profile manager and there is only one default profile showing in the local and root directories. This is the default one and is the one that shows up when the user profile selection window appears. I can copy it with another name and then continue into thunderbird but the new profile doesn't show in file explorer and doesn't appear the next time I start thunderbird and the select user profile window appears again. It seems the default profile is the only "official" one as far as thunderbird is concerned. There are lots of profiles listed in File Explorer in the profile directory path. But they don't show in profile manager or in the user selection window list. Something is pointing to the wrong place, I am sure. Can I delete the profiles that seem to be hidden? They all incorporate my name , see attached. Maybe one of these has a manage _only_at_launch value set to true. But as I said these profiles don't show in the profile manager. Very puzzling!

The only profiles that TB recognizes are the ones listed in profiles.ini, in the Thunderbird folder. I think that Profile Manager reads the ini file on startup. You can create new profiles with PM and either have it empty, except for default files, or choose an existing folder which is a profile, although not one listed in the ini.

If you were to rename profiles.ini or remove it, TB would create a new ini as well as an empty profile. If you add the accounts to the new profile, data from the old profile can be transferred manually. I expect the new profile would work properly with PM launching each time or not.

Success!! I renamed profiles.ini and restarted TB. I had to put the IMAP and SMTP details in again but TB now starts with no further messing about. One small moan! How can I recover the stored email folders that I had previously? Thanks for your help.

Close TB, open the old profile folder, open Mail/<popservername>, Mail/Local Folders and ImapMail/<imapservername> and look for the mbox files - large files with no extension, named after folders - and also in sbd subfolders. Copy the mbox files to Mail/Local Folders of the new profile. Restart TB, and the folders should appear under Local Folders in the Folder Pane.

I have followed your instructions but cannot find any mbox files , the nearest is some files with an .mozmsg extension. I have also found the new version of thunderbird has ignored all my address book data. I believe I need to find .mab files , but I can't find them either. Something is not right with Thunderbird and it's very frustrating. Also in your last post you mention sbd sub folders. What are they and where do I find them?

If you have a POP account, there is a folder in the Mail subfolder of the profile named after the server, e.g. pop.gmail.com. In Mail/pop.gmail.com there is a file named Inbox and Inbox.msf. Inbox is an mbox file. In Mail/Local Folders there may be other files e.g. Specialfolder and Specialfolder.msf, and foldername.sbd which is a subdirectory, which may also contain mbox files.

Look in the old profile folder for abook.sqlite and history.sqlite (Personal Address Book and Collected Addresses) and copy them into the new profile folder.