You can download the 64-bit version of the current 102 release and remove both 32-bit and 64-bit versions you currently have installed.

• (64-bit Firefox) "C:\Program Files\Mozilla Firefox\"
• (32-bit Firefox) "C:\Program Files (x86)\Mozilla Firefox\"

Then reinstall the 64-bit Firefox 102.0 version you previously downloaded.

• https://www.mozilla.org/en-US/firefox/all/#product-desktop-release

Thank you for your answer cor-el. Just confirming that I remove (delete) the existing 32-bit and 64-bit versions before reinstalling the 64-bit Firefox 102.0 version?

When activated, will the new downloaded version have my existing bookmarks and stored passwords?

You can possibly keep the 64-bit version and reinstall a newly downloaded copy like I posted above. That increase the possibility that Firefox reuses your old profile. If Firefox insists in creating a new profile then remove compatibility.ini in the profile.

• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

See also:

• https://support.mozilla.org/en-US/kb/recover-user-data-missing-after-firefox-update

So appreciate your help cor-el - it all worked perfectly and I have all my bookmarks, etc. Thank you.

This issue would normally be fixed with a clean reinstall that involved deleting the Firefox program folder.

(64-bit Firefox) "C:\Program Files\Mozilla Firefox\" (32-bit Firefox) "C:\Program Files (x86)\Mozilla Firefox\"

An error message about XPCOM missing or about platform version usually happens because of a failed Firefox update that left you with a mixture of old and updated files in the Firefox program folder. This can happen in case security software was keeping a handle of some of the files in the Firefox program folder preventing Firefox from replacing all the files. You can do a clean reinstall to ensure that all files are replaced. You may have to disable security software temporarily in case the problem persists.