Last night my new Win 8.1 Dell PC decided it needed to install updates. I chose to switch off until restarting this morning. It said "Loading Windows updates. Do not switch off your computer". Being a good boy, I obeyed and waited as it got to 81% complete ...... and waited, and waited, had breakfast, went for a walk, had more breakfast and still it said 81%, please wait. In all it had now been 1 hr 40 minutes!
At this point I was about to ring up that nice Dell man in India when I decided to turn off the PC and try again. THIS time it sailed through 81% and reached 100% complete in no time. PC works fine! What the heck was going on?