Flashing ROM...
ive rooted my desirehd some years ago using ace hack kit and that kept me busy and satisfied until now. i really need to upgrade to the newer version of android that my device can run smooth but without loosing my root can anyone advise ?? keep in mind that until now i never tried to flash anything to my device am completely noob but i fell in love with the possibilities root gave me on software and i dont want to loose it.
No worries, Since you're worried regarding your root access. All Roms that you see here are custom ROMs and comes with Prerooted so don't afraid of flashing it.
Just to be safe side, Install latest recovery either CWM or 4ext and backup your Stock or any custom ROM you're on.
Flash Any ROM made for Desire HD. But be aware that if you're S-ON then flash Boot.IMG before or after complete flashing your ROM via HBoot in order to get proper connectivity and your ROM to work properly. If you're S-Off already then no need to flash boot.img since system will take care of it.
Even then you're worried regarding how to flash then type in YouTube for How to flash custom Ron for Desire HD. So that you'll get exact idea about it.
Very important: Make sure your radio and hboot is latest. Or you should running last official update from HTC which is gingerbread 2.3.5 Otherwise you need to upgrade that first prior to flash any custom ROM from any source.
Get on 4.4.3 its latest yet stable.