That sounds a bit confusing. I'm thinking maybe you mean 12 = Dec and 17 = date eg: 17th Dec year unknown So, 19th Dec is only 2 days later. I'm wondering if you are really talking about 'profiles'.

One profile contains everything - your address books, your calendars, all your various mail accounts for different email addresses, all your preferences - the lot. Most people will only have one profile name folder although several may have two. A profile name folder usually takes this sort of naming using letters and numbers: 'abc1234x.default' or 'abc1234x.default release'

Perhaps it would be a good idea to post an image showing what you are talking about.

On Windows 11 if everything is stored in default location you will find your Profiles in this location:

• In windows search type : %Appdata% - see image as guide
• Select %Appdata% file folder
• Click on 'Roaming'
• The 'Thunderbird' folder contains everything - you would get a copy of that if intending to perform a backup.
• Click on 'Thunderbird to see contents
• clickon the 'Profiles' folder to see list of Profiles
• The Profiles folder will show a list of all your 'profile' name folders.

You can also see what Profiles are installed via Thunderbird program In Thunderbird

• Help > Troubleshooting information
• Under 'Application Basics' - near the bottom locate 'Profiles' and click on 'about:profiles'
• It opens in a new tab and it will show a list of your 'profiles' and also tell you which profile is the current default being used.

Please note: If you have Firefox then it will also use profiles. Windows will also create some 'profile' folders in the 'Local' folder which it uses to help cache data.

Thank you. You reply does help. However, it looks likes Thunder bird creates a new profile when ever changes are made to the T-bird layout. For example, I added feeds on December 19, 2024. Right now in the profile folder, there are 4 profiles. Two contain the same items but with different folder dates (Dec 17, 2024 and Dec 19 2024) dates. Two other folders dated both dated Dec 17, 2024 have one each which is named v times.json. So is it safe to deleted the Dec 17 Profile? Thanks again and have a Merry Christmas

re : Two other folders dated both dated Dec 17, 2024 have one each which is named v times.json.

If it only has the one file then these can be deleted.

re : Two contain the same items but with different folder dates (Dec 17, 2024 and Dec 19 2024) dates.

If the 'about:profiles' says you are currently - set as default - using the one dated Dec 19 2024 then... I would Exit Thunderbird, access Profiles folder and 'move' the one dated 17th Dec to another location like your Desktop and start Thundebird to double check everything still works ok.