As an AOL user for the past 5 years I had a similar problem when I had to clean out my whole OS and reinstall.
What I discovered then was that the AOL PFC is in it's own code that will not open in other applications. My solution was to stay with AOL.
As far as I could figure out, the only way to do this would be to go through saved messages, open them one by one and copy and paste them into Wordpad, or some other WP application where they can be saved as text.
A Canadian friend had the problem of her PC crashing totally, and asked if I could send a back-up of all mails sent and received over the pat year(both on AOL). I dis what I have just described and sent the whole history as a 'word doc'.