Testing a post from the Windows Live Writer. I had to only enable the “Blogger XML-RPC publishing protocols” and it was set to go!
I like Windows Live Writer since it enables you to write posts on your local machine and just save the draft and continue on it later on as you need.
Still trying to take care of some kinks as the WordPress theme is not working very well on the Windows Live Writer. BTW you can download the writer from : http://windows.microsoft.com/en-US/windows-live/essentials-other-programs. It is part of the “Windows Live” program suite (and is free)
Also if you have any issues with your WordPress theme while working with Windows Live Writer see this post : http://www.lehsys.com/2010/05/windows-live-writer-test/