Where are the mail files located on C: drive? The shop that repaired/installed Win 7 Pro deleted my address book files, or I won't have an address book.

I cannot find the mail files on Windows 7, which is new to me. I am afraid they might be in one of the locked folders. For the old Mozilla, those files were down several layers under Documents and Settings, which is a locked folder, but I understand that in Win 7, it is not the same thing, and those files may be somewhere else. But I don't know where that might be. The Local Settings folder is also locked. Does anyone know where those mail files (as in my profile) might be? If I can't find these and add my address book files, I'll have to rebuild the address book one at a time. Aaarrrrggghhh.