I was having the problem with messages not deleting from Windows Live Mail, as described in the first post. I ran the repair as described and then started getting the x800C01552 error. I uninstalled, as described, deleted the folders advised, re-installed and am STILL having the problem. I'm extremely frustrated. I need my saved emails and my contact list, and while having messages that wouldn't delete was annoying, I'm fairly angry that your 'advice' made the program stop working completely.
Please help.