How do I factory reset my HTC Desire?
You should be able to wipe via the recovery however, this will wipe all the data on the device including contacts, apps, pictures and videos.


Turn the power off. If your HTC Desire is frozen, pull the battery out and reinsert it
Hold the Volume Down button
Press and release the Power button
You are now presented with a menu that allows for Fastbook, Recovery, Clear Storage, and Simlock
Select Recovery
On the next screen press Volume Up and Power
You should then see the "Android System Recovery"
Select the 'Wipe data/factory reset' option
You may need to confirm your choice (i don't want to wipe the device i have so not 100% sure)