its always apear wheels and then sad smiley on lumia 620 the screen

[WPCentral Question]

when i try to upgrade windows 10 software its almost to finished and my phone set on the wheels but that time its apeared the wheels and then sad smiley on the screen and the phone turned off.

 

[Ed Boland]

Make sure the phone is fully charged. Plug it into the wall charger for a bit, restart it (hold down power and volume down buttons together for about 10 seconds until it vibrates) and try again. Let us know what happens...