I followed a link from Eudora 8.0 help menu and find that this site is not much help.
I was able to import my address book from Eudora 7.xx but not the mail, the mailboxes, or the filters. With Eudora 7.xx, one can just copy the files into the proper address space but, apparently, Eudora 8.0 uses hidden files as the Windows search feature cannot find them.
Larry