what do the critical down load warning mean

[WPCentral Question]

turn phone on and it pops up but do not tell what to do

 

[srikanth reddy4]

Go to phone update settings and download

 

[jontyfernz]

turn phone on and it pops up but do not tell what to do

use wifi and download it.Its usually before denim so you can install the update on the sd card if your phone memory is only 4gb