Solution 1: Try holding the power button until it turns off. Then start it up again.
Solution 2: If it won't turn off, take out the battery and unplug it.
Solution 3: If it just continues restarting, even after turning it off and on again, try waiting 12 hours straight with it on and plugged in. If it loads from there after many many hours, go to your C drive, right click it, properties, security, advanced, owner and change it to administrators, and apply that to all objects and sub objects.
Solution 4: Go to a professional, or read another post.