Today I came across an issue with a Nokia Lumia 620. I had to reset a Nokia Lumia 620 to its factory defaults. For some reason the normal reset function on the phone did not work so I had to Hard Reset my Nokia Lumia 620 Windows Phone. Doing the normal reset you need to go to the Settings Menu and then select About. Under About, you will have a RESET YOUR PHONE option. When you select this option and confirmed it, your phone will display spinning gears on the screen for about 5-15 min and then go back to the Welcome Screen.
In my case the Nokia Lumia 620 stayed on the spinning gears on the screen. Even if I take the battery out and put it back in, the Windows 8 Phone will go back to the spinning gears. I had to do a search and found a solution to Hard Reset my Nokia Lumia 620 Windows Phone.
Hard Resetting my Nokia Lumia 620
First of all, make sure your Nokia Lumia is fully charged. While the screen is displaying the spinning gears press the Hard Reset key combination.
Hold the POWER Button, VOLUME DOWN Button and CAMERA Button.
Wait until the Windows 8 Phone vibrates and then release only the POWER Button.
Keep the VOLUME DOWN Button and CAMERA Button down for another 5 seconds until the gears disappear.
Then leave the phone for 5-15 minutes. Hard Reset my Nokia Lumia 620 Windows Phone should now be complete and the phone should go straight to the Welcome Screen.