To protect the privacy of your data on Nokia Lumia 800, you can set a password as a key that only you know to unlock your phone.
Learn how to set a password on your Nokia Lumia 800 here:
1. Press the Start key to go to the start screen.
2. Select the right arrow .
3. Next tap Settings .
4. Then choose Lock + wallpaper.
5. Switch Password to On .
6. Enter a 4 - digits password.
7. Tap the Require a password after. Set the length of time you want the phone is locked automatically.
From now on, anyone who wants to access your data on Nokia Lumia 800 has to get the password right first.
To unlock the phone with password, press the power key on the right side, under the volume keys. Drag the lock screen up and enter the password.