Windows Live Mail message file for email account disconnected from email account name.

Windows Live Mail is working on Win 7. I tried to import messages from another computer which worked. To be safe, I saved the original email files that were in the WLM folder. Then something happened. The email account does not access the data file and the name of the file is not the same as the email account name. I tried copying the saved file back into the WLM folder but no luck. I even tried creating a new email account and tried to make it find the saved file which I copied to the WLM filder but no luck. . I have all the messages but I can't make WLM email account sync with them. How do I get them connected?  Thanks.