In order to hard reset a O2 Cosmo, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
O2 Cosmo device will be brought back to the default configuration of a brand new device.
1. Turn off the phone.
2. Now press-hold Power and both Softkeys simultaneously for two seconds.
3. Press 0 to confirm the hard reset. Done! Watch as your phone resets & restarts.