In order to hard reset a O2 XDA Comet, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
O2 XDA Comet device will be brought back to the default configuration of a brand new device.
1. Pick up stylus. Use it to press & hold Reset and Power buttons simultaneously.
2. Allow your phone to reset and restart. That is all.