Can’t Delete Duplicated Emails

I upgraded to Windows 10, didn't like it, and went back to Windows 7.  Since then, my email account is working fine, but my wife's email is having problems.  We both use Windows Live Mail 2011.  When she opens her email account, a separate window appears that says "Recovering the Windows Live Mail Database".  She now has over 1000 messages in her Deleted Items folder.  Each one is duplicated.  I can delete the one flagged as unread (I think, it is bolded), but not the duplicate that has been read as it is dithered out.  When I try to delete one of the dithered ones, a window appears that says "an unknown error occurred".  I set her program to empty the deleted items folder when closing the email account, but it didn't help.  The duplicates are still there.  How do I get rid of all these unwanted emails?