I had some problem with Outlook Express - it loaded the same mails many times and then crashed. I rebooted the system, opened the application, ans the same thing again. Maybe after the seventh time, the sapplication seemed to function well. However, all the mails on the INBOX-folder were lost except the new ones. Following the advice in a relevant article in EE, I used the Express Repair Tool - free 30 trial version.
On the first run, it recovered some hundreds of lost mails. I did not know how to save them, and I closed the application, and opened Outlook Express. They had not appeared there. And when opening again the Repair Tool, the recovered mails were not there, either. In the proper folder the size of the file INBOX.DBX had diminished to a fraction of the previous one, meaning a total loss!
I suppose I did something wrong, but I have know idea what!