Moving windows
 

I downloaded a UI that has windows which apparently can't be moved (Chat window and others)

How do I position these windows where I want them?

if they have titlebars, you can right-click the titlebar, or another part of the window and click on *Lock to unlock them. Or, if they do not have titlebars, you probably still need to unlock the window, and if it's a chat window for example, the easiest way without having to edit your .xml is to size it to location you want it. Make sense? Some windows like the buff window are often made with invisible backgrounds, and it's kind of a trial and error until you find where you can drag the window. Hope this helps some! :)