Rooting Desire permanently If I root my Desire permanently  can I reset it to default manufacturers settings by installing official android version?
Whenever you root your device, you are adding root access to the current OS. If you just perform the Factory Reset, it will retain root (as this just deletes user data), but if you restore the stock image, it will completely wipe the OS and will put the system back as HTC intended it (which would remove root). You would then need to re-root the device.