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 before factory reset. 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. With or without insurance, if your cell phone lost, damaged or stolen at least your invaluable data is backed up in a safe place. If you are about to sell your phone and you want to wipe your personal data, or if your phone affected with virus you have to do a hard reset. In some cases, you can delete the forgotten password or lock pattern from your device as well.
Nokia C7-00 hard reset
Please use this code for hard reset. Do not use the 4 key combo only in case as last resort!
You can format your device by typing *#7370# in standby mode. Before the device is reset, you need to provide the lock code. The default lock code is 12345.
Some Nokia phone can be reset via this menu option Press menu button or enter Menu > Settings > Phone > Phone management > Factory settings > Delete data and restore > YES
Nokia C7-00 hard reset using hardware keys
Be careful!!! It is possible you won't be able to reinstall apps e.g OVI after this methode. Use hard reset code instead.
Turn off yor Nokia C7. Press both Volume down + Camera + Home + POWER ON cell phone.
Formatting the device will permanently erase all user data and settings as well as add-on applications and operator specific settings.