If you are using Wordpress and Windows Live Writer together and you are having problems, maybe these solutions from Wordpress.org can help you.

• Image uploading fails
• Posting fails for some blogs that don’t use UTF-8, ISO-8859-1, or US-ASCII encodings
• Bad Behavior plugin doesn’t like Windows Live Writer
• Invalid response from blogger.getUsersBlog
• Non-ASCII characters render incorrectly on UTF-8 encoded blogs
• ArgumentOutOfRangeException while attempting to open posts from WordPress blogs