Dell Inspiron 7353 stuck installing updates?

I purchased a Dell Inspiron 7353 laptop yesterday afternoon. In the evening, I plugged it in, turned it on, answered the language/keyboard questions, accepted terms of use and then it started "installing critical updates". Well, it's been doing that for 13 HOURS now. The messages on the screen alternate between "Installing Critical Updates. Don't turn off your PC", "This might take a while. Don't turn off your PC", "We're still working. Don't turn off your PC" and "We'll let you know when we've finished. Don't turn off your PC." How long should this actually take? This seems a bit extreme.