Before you buy a new cell phone or new tablet, please try the following procedure to repair your device. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card. It is impossible to recover your data after doing a hard reset, so online backup is always important. For all of your data, a backup should be done on an external device, hard drive, raid system or media.
Nokia N8 hard reset with keys buttons
With the phone turned off, press VOLUME DOWN + CAMERA key + MENU + POWER key. for 1 minute (Maybe not working!!! Pls confirm...)
or
Main Menu>Settings>Phone>Phone mgmt.>Factory Settings>Delete Data and Restore

OR
Type *#7370# then select YES. Default phone lock code 12345

