#2 The random yccklof6.default name is different for your install.
Open Thunderbird> Tools> Account Settings> Local Folders>
Local directory>
C:\Users\ Your name \AppData\Roaming\Thunderbird\Profiles\yccklof6.default\Mail
Your old email is there. You can copy and paste the folders into your new folder from the new install.
Inbox.sbd
Sent.sbd
Drafts.sbd
Templates.sbd
none of it is there, it deleted everything which is just plain stupid, normally programs reinstall and use the existing saved databases, but these snot nosed kids without adult supervision appear to be not so smart. Maybe they should have called their Mommy for advice first??