I just put the OS back on m other drive. I would like to get my email addresses from the old drive. Does anyone know what directory these are in?

What's your OS? For XP, it's in something like...
C:\Documents and Settings\userid\Application Data\Thunderbird\Profiles

IN your profile, there's a file called abook.mab. I suspect that's address book...

Ok, I'll look there. The store was supposed to set it up, but they wern't very helpful