I have been using Windows Live Writer almost exclusively for creating all of my WordPress blog content for almost a month now. Over the month I have found some missing functionality in the core Live Writer product but plugins you can download and install that add this missing functionality.
One such plugin is the Live Writer Code Snippet plugin which allows you to cut/paste various source code and have it display really neat with line numbers inside your WordPress blog post.
With the Live Writer Code Snippet, you would just click on the "Code Snippet" link on your right hand sidebar or click on Insert –> Code Snippet from top of the Live Writer menu:
Just paste the code into the top portion of the Code Snippet plugin and select the scripting language that you are pasting:
Click on the Insert button and you will have a nifty little code box showing your source code that looks like below:
You can even configure to have a solid color background instead of alternating line colors, no line numbers, and other minor style customizations. The best thing about using Code Snippet for Windows Live Writer is you don’t need to install a WordPress source code plug-in to make your code show up in this format. So this means you avoid the overhead of installing and configuring one more PHP plugin on all your blogs you want to write on.
If you use Windows Live Writer for WordPress then you should add Live Writer Code Snippet plugin to your arsenal of plugins to help showcase your source code in a clean manner that is easy for users to cut/paste from.