Sometimes when you try to set up a new blog account with the Windows Live Writer the installation process might be interrupted by an error message:

Invalid Server Response - The response to the blogger.getUsersBlogs method received from the weblog server was invalid: Invalid response document returned from XmlRpc server.

Unfortunately there is more than one reason for this error message and maybe you have to try them all.

Php problem

There is an error in the php modul. Open the xmlrpc.php in your wordpress root directory and enter this code on the first line:

$HTTP_RAW_POST_DATA = file_get_contents(“php://input”);

Htaccess problem

There is a conflict in the htaccess file, enter the following code somewhere in the htaccess file:

<Files xmlrpc.php>
SecFilterInheritance Off
</Files>

PlugIn conflict

A plugin is causing a conflict. Try to deactivate all plugins and repeat the setup.

Lowercase vs. capital letters

Wordpress runs on Apache and on apache lowercase matters. Login with your FTP program and check if the xmlrpc.php is written in lowercase if not upload again all files in the right format.

Note: It happens often after a Wordpress update

XMLRPC activated?

With Wordpress 2.6 there is the a new option (wordpress >> write) to deactivate the xmlprc api (standard: deactivated) Box must be checked