I'm going by a checklist from Ready to Fly Quads wiki. Here......
http://www.readytoflyquads.com/the-rtf-wiki
First I extracted the files from the Multiwii 2.3 zip file. It says to install but I never get that option it says Run or cancel. So after I ran the program I shut off the computer for a lil over a minute and restarted it and ran the program it started up fine and just to make sure I shut it down again and restarted again after another minute.
The MW 2.3 still starts up fine.