First method:

  1. Make sure, that your cell phone is on. Hard Reset SONY ERICSSON K858
  2. Next on: Menu -> Settings -> General -> Master reset.
  3. Confirm operation, and follow the instructions that appear.
  4. Success! device is ready to work properly.

Second method:

  1. Back up your important files, and download PC Companion from here: http://www.sonymobile.com/gb/tools/pc-companion/
  2. After installation you will see window with 4 options.
    HardReset SONY ERICSSON K858
  3. Now hover your mouse over the option "Support Zone Now!" and click "Start".
    Factory Reset SONY ERICSSON K858
  4. Next plese wait, until your program Install a suitable additive.
  5. Afterwards from the window with 3 options choose "Phone / Tablet Software Update", and click "Start".
    Master Reset SONY ERICSSON K858
  6. Then click to "repair my phone / tablet".
    Permanently delete data from SONY ERICSSON K858
  7. Accept all informations.
    Wipe data SONY ERICSSON K858
    Format SONY ERICSSON K858
  8. Now your program will run "preparing computer for software update".
    Restore SONY ERICSSON K858
  9. Select your model.
    Remove screen password SONY ERICSSON K858
  10. After that you will see window with informations.
    Remove Screen Lock SONY ERICSSON K858
  11. Follow the instructions, and connect your device into your Personal Computer.
  12. Success!

Hard Reset will erase all of your data
All described operations you are doing at your own risk.

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