Keep your finger on the power button till it shuts off.
Next time u boot it might bring up a menu offering u various boot options, choose boot windows normally and press return.
Windows does this every now and again, its usually a program running in the background that for some reason windows cant terminate, so it waits a bit, then it waits more........
edit: Javon A, that registry cleaner thing your advertising below looks dodgy.
I love the way their website gives a completely false report on your computers status and there are over 10 links to download the .exe (including 2 on the banner at the top) on the homepage.
The download might be "100% free" but looking at their testimonials (which look made up as well, its weird that most of them have the same bad grammar lol), several mention "best software of its type iv ever purchased" or "good value for money", i reckon u will have 2 fork out the folding stuff at some point, probably after its `found` these errors (yup, tis listed at $39 on other sites).
So its not free, liars. wouldn't touch it with a bargepole lol
If u want a registry cleaner, get the freeware ccleaner from http://www.ccleaner.com/