Hmm, what is your goal? Are you hoping to have two Thunderbird shortcuts leading to different mailboxes? The built-in way to do that is to create different profiles. This article has more information on that: Use multiple profiles in Thunderbird.

This might be a duplicate.

I am NOT trying to have two Thunderbirds going. the one that I have used many years (now version 24.0) has suddenly started doing strange things (I just installed Windows 8.1)

1. It "vanishes" my Deletes - it does NOT put them in the trash folder. They just disappear.

2. I cannot read a PPS file while it is attached to an e-mail. I have to save it to my desktop first and _then_ I can read it

3. There IS a 3rd thing but I cannot remember it at this moment.

Well you need to fix the problems. This is not a Microsoft product that areinstalling fixes everything because uninstalling deletes everything.

2. Tools menu (ALt+T) > Options > attachments and correct the derfault handler for PPS files.... or delete it/