WARNING! By master resetting the Lumia 435 you will delete all personal data stored on the phone’s internal memory, including media files, downloaded content, contacts and so on. Contents on the SIM and SD cards will not be affected. All settings will be restored to factory values.

NOTE: Before master resetting the phone you can visit this thread to learn how you can back up and restore your data pre and post-reset.

Master Reset via Settings:

  1. While viewing the Start screen, swipe left
  2. Scroll to and tap “Settings”
  3. Tap “about” > “reset your phone”
  4. Read the warning message and tap “Yes”
  5. Tap “Yes” one more time to confirm and reset the phone

Master Reset using Hardware Keys:

NOTE: Master resetting via hardware keys has the same effect as any other factory reset. All personal data will be removed and settings will be restored to factory values. Use this method of reset only if you are unable to reset the phone via settings.

  1. If necessary, turn off your smartphone
  2. Press and hold “Volume Down”
  3. Press the “Power" button to turn on the phone
  4. Once the phone vibrates, release the “Power” key but continue holding “Volume Down”
  5. When an exclamation mark shows on the screen, release all hardware buttons
  6. Perform the following button press sequence to reset the phone:
    • Press “Volume Up” > “Volume Down” > “Power” > “Volume Down”
  7. The phone should now automatically reset. During this time you should see two gears rotating on the display. The process can take up to 5 minutes or more.

Check for Newer Software Versions:

NOTE: After you factory reset your phone it’s recommended to check and see if there are any software updates available for download. To do this:

  1. Swipe the Start screen left
  2. From “applications”, tap “Settings”
  3. Tap “About” > “More info”
  4. Check the “Firmware version number” and see if an update is available. If necessary follow the on-screen prompts to download and install it

See More: Microsoft Lumia 435: Master Reset & Check for Software Updates