[Desire HD Android Development] hamdir:
these instructions are intended for those who have root and S-OFF yet still on stock 1.32.405.3, the new update breaks superuser and overwrites both recovery and hboot, if you follow my steps it should all work fine and still have root, no wipe is needed

Info about this update:

1.72.405.3_R2 Update: improve system performance and camera feature enhancements

Requirements for this method:

Clockwork recovery, ENG S-OFF and radio S-OFF

unless you have radio s-off you can't flash the new radio, if you flash it without radio s-off you will loose root.

radio s-off is easy and insures you never loose s-off again, you need to have it before you apply the update

One click Radio S-OFF, SimUnlock (Easy Root Guide)

i recommend you make a nandroid backup first from clockwork recovery

Applying 1.72.405.3

Download the new OTA if you have it in the download folder you or from here

http://dl.dropbox.com/u/8076202/OTA_Ace_HTC_WWE_1_72_405_3_R2-1_32_405_6_release_1632939lowfu0y78jktpp2.zip

copy the OTA file to the root of your sdcard and rename it to update.zip

reboot into clockwork recovery and choose apply update.zip, clockwork recovery will apply the OTA safely without overwriting HBOOT and recovery

reboot, now you have android 2.2.1 and build 1.72.405.3, however clockwork didn't install the new kernel so wifi will break, you will need to flash the supplied kernel in the OTA

Re-flashing the kernel

download the original 1.72.405.3 kernel (extracted from the RUU) http://www.multiupload.com/APNFJJVGWI

Extract the boot.img file to the /tools folder of your Android SDK

Reboot your device into bootloader mode and select fast boot mode (select restart and keep holding down volume down + power, never mind the stupid vibration)

From an elevated command prompt, browse to the /tools folder of the Android SDK

Once in the /tools folder, type (without quotes) "fastboot flash boot boot.img"

Wait until the send and write operations are completed (this may take a few minutes)

Reboot your device

Restoring SU

Once rebooted, uninstall superuser (since it keeps crashing when giving permissions) this step is very important

download the old su package from here http://www.multiupload.com/YTL0P497YR

unpack files to SDCARD

boot to Clockwork recovery

(DHD CWM menu) mount /sytem

(DHD CWM menu) mount /sdcard

(PC cmd prompt sdk tools) adb shell

# cp /sdcard/su /system/bin/

# cp /sdcard/Superuser.apk /system/app/

# ln -s /system/bin/su /system/xbin/su

# chmod 06555 /system/bin/su

# exit

(DHD CWM menu) umount /sytem

(DHD CWM menu) umount /sdcard

reboot

download BusyBox from market

Flashing the New radio don't install the new radio unless you have Radio S-OFF

you can download and install the new radio by following the instructions in here

The HTC Desire HD Radio Thread

Once completed you should have the following software information:

Andorid version: 2.2.1

Baseband version: 12.28e.60.140fU_26.04.02.17_M2

Kernel version: 2.6.32.21.-g3d0aaff / htc-kernel@and18-2#1 / Wed Dec 1 17:09:51 CST 2010

Build nuber: 1.72.405.3.CL296490 release-keys

Software number: 1.72.405.3

Browser version: WebKit 3.1

for those struggling with sdk commands check this post xdaforums.com/showpost.php?p=10068129&postcount=59

these steps and files were collected from various members, all thanks goes to them

as usual i'm not responsible if all hell breaks loose in your Desire HD

[update 1] working superuser patch http://xdaforums.com/showthread.php?t=886999

[update 2] downgrade back to 1.32 guide http://xdaforums.com/showthread.php?t=905003