auto update changed my 64-bit to 32-bit

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Post Posted January 4th, 2019, 1:42 pm

The Tbird auto update updated my 64-bit version to 32-bit version.

Do I have a problem?

Is there a way to fix the update?



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Post Posted January 4th, 2019, 2:29 pm

There is no official 64bit version of Thunderbird for Windows. Did you intentionally download and install the unofficial, untested 64bit version?


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Post Posted January 4th, 2019, 2:52 pm

The Win64 builds of Thunderbird 60.0 are Not officially supported which is why they are not listed on

Thunderbird changed it's build process to move it into line with the Firefox process. A side effect is a 64bit build (for Windows) appearing in the release folders by accident.

Unlike for Mac OSX and Linux where 64-bit builds were actually needed to run, the 32-bit works just fine on 64-bit Windows thanks to WOW64. The Win64 Releases of Thunderbird may not be officially supported until sometime in 2019


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Post Posted January 4th, 2019, 6:13 pm

I installed the 64 bit version of 60 and kept it long enough for it to go through two auto-updates. It didn't convert it to a 32-bit version. So its not clear why you have this problem. Perhaps it was due to your using 52.*?

If you want to stick with a 64 bit version (IMHO it is not noticeably faster or smaller, so its not worth the risk) I suggest you uninstall your current version and install the latest 64-bit version . Uninstalling doesn't delete your profile, which stores your downloaded mail, address books, settings, add-ons etc.

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