This challenge is simple.  Write code that shows what looks exactly like a complete reboot of the computer. It must not show anything on-screen that shows it is not a full reboot and should end at the log-in screen you would get after rebooting.

**Rules**

 1. You can choose any OS you like to imitate. For example you can reboot into Linux from Windows, Mac from Linux, or any other combination you choose.   
 2. The code should display the full reboot full-screen with no signs that it isn't real.
 3. This is a popularity contest so the cooler it looks, the better it is. 
4. The code must be completely harmless, perform no actual rebooting, and be easy to quit at any point.
5. If you need to use external images to make the reboot look more realistic, then your code should automatically grab them from the web.
6. Your code should be self-contained, only relying on standard freely available libraries or tools, and must be easily executable by reading the instructions you provide.

As it is a popularity contest, I will award the win to the answer with the highest number of votes on June 1, 2014.

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Following a request to narrow the question, here is an additional rule,
the system should imitate any version of Windows or the Mint, Ubuntu, Debian, Fedora, Archlinux or Mageia distributions of Linux or OS X. For extra coolness, you should shut down in one and open in the other.

Interested people may want to look at https://codegolf.stackexchange.com/questions/26697/pitch-dark-earth-hour-remembrance where a number of ways are suggested for using the full screen even when starting in an xterm.