THIS PROCEDURE IS OBSOLETE, PLEASE DO OUR NEW HOW TO ROOT AND LOAD A CUSTOM ROM PROCEDURE:
I. Before You Begin
1. You MUST have done our How To Root the HTC Desire. If you haven’t, go do it and then come back here to continue.
II. Download and the Recovery Image Package to Your Phone
1. Download the recovery package
2. Save the .zip file to the root of your SD card and rename it to update (NOT in any folders, just on the sd card itself. Do NOT extract it. It should be named update and be a .zip file).
II. Download the ROM You Want
1. Goto our HTC Desire ROMs section on our site and choose from the ROMs there. Download the one you want and save it to your computer (do NOT extract it, leave it as a .zip).
2. Plug your phone in via USB cable and mount the sd card so we can transfer files to it.
3. Copy the ROM .zip file to the root of your sdcard (NOT in any folders just on the sd card itself).
4. Now, turn the phone off and turn it back on by holding down Volume Down and Power until the Bootloader mode comes up.
5. Using the volume buttons and power to select, navigate and choose Recovery.
6. Push Volume Up and Power to get the recovery menu to appear.
7. Select Apply sdcard:update.zip (This should launch the recovery package).
8. In the new recovery menu on your phone, navigate using the trackpad to Wipe and click it. Then click Wipe data/factory reset.
9. Once it is done wiping, click Volume Down to go back to the main menu and now select Flash zip from sdcard and choose the .zip file you downloaded and saved to your sd card just now.
10. Once it is done flashing, select Reboot and your all set! You are now running your custom ROM. Enjoy!