I would check the validity of the outlook PST. Perhaps it is not valid.

What is the path and name that TBird is looking for in Outlook? I have....C:\Documents and Settings\youmei\Local Settings\Application Data\Microsoft\Outlook... and inside there are 3 files...archive.pst, outlook.pst & backup.pst

I pasted the Outlook pst file in TB, all that does is make a folder with the same name when you open the TB program. Still nothing is there when you click it. Tried posting it into an empty folder still nothing shows when you open the folder in the TB program. TB cannot process the Outlook file at that point. OK lets go to the beginning. Why does TB give me the ...default client... message and nothing happens? Either TB cannot find the Outlook file or it cannot do anything with what it finds. Assume that TB can process what it finds, then it doesn't find anything or it is blinded. I can fix anything that's not broken, so the TB import function of Outlook must be broken. Uncle

Sorry guys, but all that about pasting and folders in TB is simply wrong.

Thunderbird asks Outlook nicely for your mail and on a piece by piece basis Outlook hands it over. No paths. no conversions for Thunderbird. Thunderbird has no idea what a PST file is. I do, it is a proprietary data format owned by Microsoft corporation. All Thunderbird knows is to ask outlook the program.

So if mail does not come over it is because Outlook does not know what it's default PST file is (the one it provides)

Alright so Outlook is another dumb computer program, but I can see the pst file and I can see my emails. Is there not someone with the knowledge of how to get the email folders in a usable way into TB? There is a pea under one of the shells.

I finally figured out a way. First got a free download of Outlook Express into the XP machine with Outlook. Then imported all old Outlook folders to OE. Then imported the folders from OE into ThunderBird on the same old XP machine. Then copied the folders from TB onto a thumb drive. Put the thumb drive into the new Windows 8.1 machine and copied the folders into TB. Then made folders with the same name in TB and VOILA!