Thunderbird email problem

When wiffies sends out a message it goes as an attachment.
She is running Windows 7 Pro 32-bit. ESET SS 5.
We called Thunderbird who switched us to a Guru. In his search
of her computer he said we had over 7000+ errors in the registry.
I regularly use Ccleaner and ESET SS to take care of those types
of problems. We did not let him continue. On my puter running
Windows 7 Pro 64-bit I have to download the message and then
it is garbage. So of the hundreds of settings for Thunderbird it is
possible I have missed one or two.
Thanks for any suggestions.

 

First of all I would open Thunderbird and hit Help > Restart with Add-ons Disabled... and see what happens.

Also look under Tools > Account Settings... look at the Signature text and check if any attachments are enabled there... Maybe signature from a file or Attach my vCard to messages is enabled.

And maybe you haven't heard of it before but there is a free program called MozBackup that can back up all your settings including add-ons for both Firefox and Thunderbird that you should look at so you can quickly restore to a working copy.