WARNING! When you master reset a phone all of your personal data stored on the internal memory will be lost. This includes media files, downloaded content, contacts etc. In addition, all of the phone’s settings will be restored to factory values.

NOTE*: Master resetting a phone will not affect data stored on the SIM and SD cards

NOTE**: Before proceeding with the master reset, you can visit this link to learn how you can back up and restore data on the Lumia 540 Dual.

Master Reset through the Settings Menu:

  1. On the Start screen, swipe left
  2. Access “Settings”
  3. Tap “about” > “reset your phone”
  4. At the warning message, tap “yes”
  5. Tap “yes” a second time to confirm and proceed with the master reset

Master Reset using Hardware Keys:

NOTE: If you are unable to master reset your phone using the method above (your phone may be crashing, freezing etc.) then you can try master resetting it through a combination of hardware buttons. Use the following method in case the other one fails:

  1. Turn off your phone
  2. Press and hold “Volume Down”
  3. Press the “Power” key to turn the phone back on
  4. Once the phone vibrates once, release the “Power” button but keep holding “Volume Down” pressed
  5. When you see an exclamation mark on the screen, release all hardware buttons
  6. Perform the following sequence of button presses in order to reset the phone:
    • Press: “Volume Up” > “Volume Down” > “Power” > “Volume Down”
  7. The Lumia 540 Dual should now automatically reset, and you should now see a couple of rotating gears on the screen

Check for OS Updates:

NOTE: Once you master reset your phone you should check and see if newer software updates are available. To check for updates:

  1. Swipe the Start screen left to “Applications”
  2. Go to “Settings”
  3. Tap “About” > “More Info”
  4. Check the “Firmware version number” and see if newer updates are available. If so, follow the on-screen prompts to download and apply them on your device

See More: Microsoft Lumia 540 Dual: Master Reset and Check for Software Updates