In order to hard reset a Siemens C62, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Siemens C62 device will be brought back to the default configuration of a brand new device.
1. Press-hold the Power button to turn the phone on.
2. Type in this code: *#9999#
3. Now wait until the phone restarts. Done.