How long does it take to install Lumia Denim on Lumia 525?

[WPCentral Question]

the two gears have been spinning for an hour. how much more time will it take?

 

[Harrie-S]

re:

the two gears have been spinning for an hour. how much more time will it take?

If they still spinning check below.
FAQ - My Lumia stays at the spinning gears - Microsoft - UK
Furthermore is you have a SD card get it also out.