I recently tried Windows 10, had a problem with it and therefore switched back to my Windows 7 operating system.  Only problem I encountered was that in my Windows Live Email accounts, I now have duplicates of all my deleted messages that won't delete.  One deletes, but the other will not.  I get the "unknown error occurred"    I now have 400 messages in my trash that I can't get rid of. 

I tried the repair option.  No success.   Any other options?