Update, I just went back to the computer for the first time today and realized it was hung on the same thing as the other day.. that is, the windows update thing. This time it's on "4 of 6", presumably after I tried shutting down last night it went into this. Again, it looks completely like actual Windows, and may well be, but I am completely disconnected from the Internet, so it's only actual Windows if it was held in resevoir or something.