Here's, a simple step by step procedure on how to hard reset the HTC Desire HD and restore it back to factory default state settings.
Please note: All data and application installed or stored will be deleted on HTC Desire HD as a result of this procedure. However, this process does not delete the data stored on the microSD memory card. Just back up it first before you proceed.
Resetting through Menu Settings
1. On the main home screen, select menu
2. Select Settings, then Privacy
3. Select Factory data reset
4. Select Reset phone
5. Enter your password if you activated it, then select Erase everything upon confirmation
If the device is frozen, the above solution will not work
1. If your HTC Desire HD is frozen, Turn the power off or then pull the battery out and inplace it back
2. Hold the Volume Down button
3. Press and hold the Power button until the device power on
4. A menu will appear that allows you to choose for Fastbook, Recovery, Clear Storage, and Simlock
5. Select Clear Storage by pressing the Volume Down button
6. Press and then release the Power button
7. A confirmation menu will appear: Volume Up for YES and Volume Down for NO
Once the wipe is complete, All data including third-party applications already deleted. The HTC Desire HD will reboot to its factory default state settings.