Make sure you aren't using the 64bit version of wow. I started a friend with the bot and troubleshot it until we figured out it was because he was running the 64bit, he switched back and it worked just fine.
Already running 32bit client, windowed, and dx9. But for some reason updating to 2.0.0.5771, it just can't attach.
Hold on, does the client HAVE to be Windowed, and can't be Windowed (Fullscreen) anymore since this update?