In order to hard reset a HP iPAQ hw6915, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
HP iPAQ hw6915 device will be brought back to the default configuration of a brand new device.
1. Power down the phone.
2. Is it off? Then press'n'hold those buttons for five seconds: Reset End Send Power.
3. After five seconds, release held buttons. The phone should now reset and restart.