The profile manager goes out of it's way to provide all possible options *except* the one that's needed most: How to simply "switch" from one profile to another profile? When a new Thunderbird installation is created, all profile operations are limited to the profiles created when Thunderbird is installed. Other profiles that are available in the right location under Users\---\AppData\Roaming\Thunderbird\Profiles\* are simply '''''ignored''''' without any possible, or at least obvious, route to switch to them and / or activate them. Why? This issue is a real problem when attempting to migrate existing Thunderbird settings, mail data, etc., from one physical workstation to another. Fortunately I found a fix by grabbing the mail\pop_account folder under the old profile and plugging that folder into the new profile. Still there was additional aggravation associated with lost settings, another import / export for the calender, etc., etc. Again, why does this have to be difficult?