HTC Desire Factory Data Reset

Internal reset - Android 2.1
"Settings" > "Privacy" > "Factory data reset"
Internal reset - Android 2.2
"Settings" > "SD & Phone S
Hard Reset:torage" > "Factory data reset"
1. Turn the power off. If your HTC Desire is frozen, pull the battery out and reinsert it
2. Hold the Volume Down button
3. Press and release the Power button
4. You are now presented with a menu that allows for Fastbook, Recovery, Clear Storage, and
Simlock
5. Select Clear Storage by pressing the Volume Down button
6. Press and release the Power button
7. Now simply confirm your decision: Volume Up for YES and Volume Down for NO
If you selected YES, all data including third-party applications will be deleted from the HTC Desire.
Once the wipe is complete, the phone will reboot to its factory fresh state.