Sounds like the installation failed or is corrupt. I suggest you completely uninstall, reboot, and try again.

Is it possible that you previously installed a 32-bit version and you are now trying to install a 64-bit version, or vice-versa? Or that you previously installed a version downloaded from the Microsoft Store and are now trying to install the one gotten directly from the Thunderbird site?

If you have not yet set up any email accounts, make sure you have deleted (or better yet, moved out of the way, for safety) these folders found in (the default locations):

C:\Users\<your Windows account>\AppData\Roaming\Thunderbird C:\Users\<your Windows account>\AppData\Local\Thunderbird

Hi Lin, Thank you for your advice. I did as you described - deleted al Thunderbird, restarted PC, and loaded new from Mozilla. As you can see on picture I now have 2 icons, load program and Thunderbird icon. It looks correct but when I push the Thunderbird icon I get the answer : not found. Can it be placed wrongly in directory ? Can I do this manually ? I appreciate your help.

Best regards Thorvald

Thar error message is different from your post. It appears you did not follow Lin's insructions. Try this: - at windows desktop, enter #appdata# in search bar and press enter. - that should open file explorer at the appdata\roaming folder - delete the thunderbird folder - start thunderbird and let us know.

Also, please get clear screenshots. a simple free one is at https://www.reasyze.com/ and is called sniptool.

Hi David, This solved my problem. enter #appdata# in search bar and press enter. - that should open file explorer at the appdata\roaming folder - delete the thunderbird folder

I have now got Thunderbird on my Windows 11 PC - great ! Thank you for your help. Regards Thorvald Antvorskov

You are very welcome. Thank you for the feedback. :)