Post Code With Dignity to Windows Live Writer is a Plugin that solves one problem: pasting code to WLW
Windows Live Writer has some serious issues when getting asked to insert large chunks of source code that should not be altered.
Even inserting clean HTML through the HTML source view will (if you go back to design view) break your HTML due to WLV trying to "tidy" and validate your HTML.
This Windows Live Writer plugin will solve the issue by inserting code as a block element in Live Writer (like a image), while still sending plain HTML to the blog.
This plugin was written with SyntaxHighlighter in mind, so it will put your code in blocks with the appropriate attributes for your language.