cc^, the 64-bit will actually install the 64-bit version over your old 32-bit version unless you do a manual override (eg select custom installation at one point) and install it in a separate folder, irrespective I understand that both installations will use the same user data (eg. "Profiles", see below). If Thunderbird does not pick up the "default" profile, see the similar question with the chosen solution provided by sfhowes, How to migrate/import accounts when moving from 32-bit to 64-bit thunderbird, which shows you how to get back the 32-bit "default" user data (default Profile) in the 64-bit version, whatever you do I recommend you take a backup of your user data ("Profile"), see Profiles - Where Thunderbird stores your messages and other user data, before installing the 64-bit version.

All the best from Stockholm.

Thank you. It opened right up after I let it install over the 32 bit. Hopefully things will keep working this time. Thanks again for you help!!

Sorry for the duplication.

Just a tip, try not to make posts that have periods in between words like Thank you...it as it is being auto flagged for moderation as possible spam links.

Thanks, I didn't realize that. Sorry for causing a problem