Stay where you are and let someone else complain to Microsoft about windows 10 bugs. Read this article; "How do I get Thunderbird on Windows 10 on the desktop home page" https://support.mozilla.org/en-US/questions/1074947. here's part; Thank you, Banban. Unfortunately, Microsoft totally deleted the Mozilla folders when it did the upgrade install, including all her emails and address book. I had to re-download and install both programs for her and reconfigure her e-mail. Thanks to Microsoft, she will have to also re-establish her address book contacts one by one.

Hi DavidSorge,

Thank you very much for the quick reply and the information. I had read the article you included in your reply, and it was one of the contributing factors to my suspicion that Windows 10 is not a supported operating system for Thunderbird in addition to the information on the System Requirements page hence my question.

I appreciate your advice to stay with the operating system I'm on.

Thunderbird and Firefox are actually developed by two completely different groups. Firefox by Mozilla for profit company and Thunderbird by a volunteer community project.

I saw in correspondence in the past few days that the chair of the Thunderbird council is using Thunderbird on Windows 10 (A surface 3 actually) without any issues. As you are already aware there are issues with the in-place Microsoft upgrade, but that is fairly easy to work around with a USB drive. As Microsoft never corrected a very similar omission in the easy transfer assistant Windows XP to Vista and Windows 7. I seriously doubt they will be changing their spots any time soon.

That the Thunderbird release page has not been updated to include Windows 10 is probably more an oversight than anything else, as a group of Volunteers we are spread somewhat thin on the ground at times. I have filed a bug requesting the page be changed Bug 1206370 refers

I think a definitive yes answer may well appear fairly promptly from the bug report. even if it is only in the form of an "Oops" comment on the bug.

Matt; What's the USB workaround?

copy your profile to a USB.

• On the start menu search type %appdata% and press enter.
• Drag the Thunderbird folder to your USB drive
• Reverse the process once W10 is installed. As %appdata% is a location windows defines, even if it moves to a new location you just go with the flow.
• Install Thunderbird on W10

Even if everything fails, you have a backup to go back to.

Oh, I think you will now find W10 on the release notes page.

Hi Matt,

Thank you so very much for all the information and for filing the bug requesting the page be changed. Yes, indeed, the page has been changed.

Also, I copied my Thunderbird profile to a USB drive. I truly appreciate this advice.