Perform a soft, factory, and alternate master reset of the device.
INSTRUCTIONS & INFO
There are multiple ways to reset your device if you are experiencing issues. The first step is to power cycle your device. Press and hold the Power/Lock button, then tap Power off. To turn the device back on, press and hold the Power/Lock button until the screen lights up. Note: If you are unable to turn your device off, remove and re-insert the battery.
A master reset reverts the device back to factory settings. It will permanently erase all personal data, preferences, settings and content such as pictures, ringtones and apps that are saved to the device. Data stored to an SD card will not be erased unless otherwise selected. It is recommended that you save (backup) important data to your SIM, SD card, or a computer before proceeding.
To begin a reset, tap the Settings icon. Note: If you are unable to access the screen to ‘Restart’ the device or if it becomes unresponsive, press and hold the Volume down and Power buttons simultaneously for 10 seconds, until the device restarts.
Tap System, then scroll to and tap About.
Tap Reset your phone.
Tap Yes to acknowledge the warning and to proceed with the reset.
Tap Yes one more time to confirm the reset.
If unable to reset the device using the above steps, try the alternate master reset method by first turning the device off.
With the device turned off, press and hold the Power + Volume Down buttons.
After the phone vibrates and you see the Microsoft logo, release Power + Volume Down buttons and quickly press and hold down the Volume Down key.
An exclamation mark (!) will appear on the display. Release the Volume Down button.
Press the following buttons in this order: Volume Up > Volume Down > Power > Volume Down.
The device will now reset. Follow the Welcome prompts to set up the device to your desired preferences.