Duplicate emails and missing folders in Windows Live Mail

Windows Live Mail acted as if it exported then imported contents [without having received command to do so] and all of a sudden many folders are missing and within the folders, the contents are confused. In many cases, the contents of one message is repeated over and over again regardless of the subject/sender/date of messages.  This also skips folders, with the same message appearing in many folders.  Any ideas as to how to recover lost folders and to solves this problem?