The problem of people losing emails (and email accounts) in Windows Live
Mail has come up several times on lists in the past few years. For a
very good description of what and how to recover, lost folders, etc, in
WLM, visit
http://powerphil.wordpress.com/2011/02/11/how-to-recover-email-after-deleted-windows-live-mail-account/
(I believe it also works in the 2012 version.) I used it myself to
recover emails. Be prepared, though, for a long wait if you lost
thousands of emails.
For answers to frequently asked questions about this list visit:
http://www.jaws-users.com/help/