"Word cannot register your account"

I don’t know whether this is the right forum to ask about a problem I am having trying to activate XML-RPC support from Microsoft Word 2007. If this is not the right forum, do you know where I should be asking this question?

I walk through the procedure to create a new WordPress account in Word, set my Picture Options/Picture provider to “My blog provider”, fill in Blog Post URL (and verify that xmlrpc.php actually exists), enter my user name and password, then click OK. I get a message that says “Word cannot register your account.” It would be nice if I was also told why but I am not. The information that pops up when I click on More Information is not helpful. None of the problems listed apply to my situation.

It would make it far more convenient for my blogging if I could make my entries from Word, because I’m going to be including a lot of screenshots and I should just be able to copy and paste them into the Word window. But I can’t do this on the “Add New Post” page of my WordPress dashboard. I’d first have to save the screenshot to a .png file with some tool (I’d use Paint Shop Pro), and then upload the image.