Taken from my rooting faq (which is specific for the desire, but Ive removed some parts and added some)

As I myself do not have a DHD, please all feel free to contribute to this. Particular lacking information is regarding S-off for DHD.

What is rooting?

Rooting is the process of gaining root access to Android. Android is based on the Linux operating system. Root access is superuser permissions (SU), much like an Administrator in Windows.

OK Great, but what does it get me?

Well, it gives you more control over your phone essentially. You can run full backup of your entire phone, control how the CPU is used by Android, save internal memory to name but a few.

What is recovery?

When you turn on your phone, the phone's bootloader loads 1 of 2 things. Android or recovery. If you use ROM manager, you can load a custom recovery instead of the HTC standard one.

Whats it for?

Booting into the custom recovery gives you the ability to flash custom roms, take backups, clear data etc.

How do I get to recovery?

If you are using rom manager (assuming you have used the option "Flash clockwork recovery"), you can reboot into recovery from there. It doesnt reallt flash recovery, it uses "Fake Flash" and downloads clockworkmod recovery and puts it on your SD card as "update.zip"

Is rooting easy?

Yep, if you download Modaco Visionary+

How will I know if it has worked?

Visionary creates an application called "superuser" within your App Drawer. This is the application that manages requests from applications for Root/SU/Superuser privileges.

Is rooting risky?

This is an app that grants Super User permissions. There isn't really much risk associated.

What's not safe about flashing radios / what are Radios?

Radio is the software required to run the physical radio which sends / receives voice and data from your phone. Its like the driver for the part of the phone that makes it a phone.

Flashing Radio's is risky because it can result in permanent brick (dead and unrepairable phone).

Do I need to flash a radio though?

Not really, You already have one. The radio is in a different part of the memory of the phone, so flashing a ROM will not over write your radio, unless the ROM includes a radio which is quite rare.

This said, certain functionality of a ROM may not work if the recommended radio is not present. I would suggest reading up on the ROM you are thinking of installing and checking your radio version from the About Phone menu. For example, 2.2's camera won't function with a pre 2.2 radio.

What about Gold Cards? Do I need one?

For rooting itself, no. However, if your phone is branded, you should definitely make one.

Why?

Branded phones need a gold card to de-brand. The goldcard Hides the true identity (branding) of the phone, allowing non-branded official roms to be installed.

Why is that helpful?

From time to time, flashing a ROM goes wrong. You can't get into recovery, you have no option but to download an official RUU (Rom upgrade utility) and restore it to stock. Some branded RUU's simply do not exist, so you need a gold card to install a generic one. Unfortunately, each gold card is individual for the phone it was made on and your phone needs to be completely working to make it.

I can't boot into recovery, there is no RUU for my carrier and I don't have a gold card

Uh oh. Crying and pleading to your gods may well be your only chance now.

Where do I check for RUU's?

Shipped ROMS

I need to send my phone back, should I return it to Stock with an RUU?

Yes. An RUU will take it completely to stock, as if it were brand new. No root, no custom recovery, no data.

Does rooting void my warranty?

Tough one, there is some debate on that. If you return it to a generic Stock if it was originally branded, provided it is official, you may be able to get away with it. HTC will know if it is the right ROM or not, but they may still fix it.

~ Has anyone any first hand experience on this? ~

Whats the best Custom ROM to flash?

That is too subjective a question to ask. Narrow down what you want. Do you want something familiar but with more options? If so get a Sense ROM. Do you want something as far from familiar as possible? Get a Vanilla AOSP ROM. Narrow down that Choice, then we'll talk some more.

How do I flash a custom ROM?

First, find a rom that you want from here:
XDA Desire HD Android Development Forum

It lists all the good roms. Be aware that you already need to be rooted. If you want to use apps2sd+, you will also need to have partitioned your card first. See the apps2sd+ FAQ in my signature.

Be aware that you may need to wipe. However, for stock / HTC sense based roms for the desire (not including ports such aas the desire HD ports), you MAY get away without doing a data wipe. AOSP (vanilla) roms will definitely need a wipe

Its always best to take a nandroid backup of your existing rom. See the Nandroid section further on in this FAQ.

Also you should backup your apps and data. Titanium Backup is a great app for this. However, I also use mybackup pro for sms and call logs, but there are alternatives out there.

If you have to wipe, this is due to an incompatibility with system settings from your old rom. See the wiping section, also further on in this FAQ.

So (based on clockworkmod recovery):

1) download you chosen ROM onto SD card
2) Do all your backups
3) Boot into recovery (you can also use ROM manager to do this, but if you need to flash more than just the rom, best to do it this way)
4) Choose "wipe data / factory reset"
5) Choose "Install zip from SD card"
6) Once complete, choose "reboot system now"

It can take 10 minutes to boot up first time, so give it this long before taking further action. If it still has not booted, pull out the battery, but ONLY when the boot animation is on. NEVER during a flashing process.

If you can obviously see the boot animation looping, this may be due to the lack of wipe. Pull the battery and boot into recovery and perform the wipe.

Once booted, if you wiped, set up the phone with network and market access and download Titanium again and whatever data restore app you used for sms (if desired).

If you wiped, be careful which option you choose to restore. You dont want to restore system settings, so "restore missing apps with data" is a good one to choose.

Now, enjoy setting up and playing with your phone.

Do I NEED S-Off?

Well, it depends what you want to do, but for most things you do not need it.

Need more info on this for DHD if anyone wishes to contribute

Rooted and/or custom ROM installed. Now what?

Get Set CPU. You can create profiles to change how your CPU acts. You can save battery this way.

Get AutoKiller. This is NOT a task killer. It clears EMPTY apps from memory. These are not apps that are running in the background or doing anything. Android does itself kill these, but this application allows you to change the thresholds of memory to do this.

Get Autostarts. Each android app listens to certain events that occur on your phone. Some apps listen to events that they do not require. This app allows you to prevent some apps listening to some events. For example, I don't want photo bucket to listen for an event based on my location. I don't need it to know where I am. TuneWiki does not need to know if I have installed an application.Have you got enough space on internal memory? If not, you could flash a ROM with A2SD+ Support. FAQ here - Please ignore links to roms as they are not for the DHD


What else can I do?

Well with custom ROMS, you may have the choice of installing a custom Kernel, which will run the CPU at the same speed as standard (998Mhz) but using less voltage (saving battery). This is called Undervolting.

At the same time, if you have SetCPU, you can overclock a kernel (if it permits) to run at a faster speed than normal, but at the same voltage as 998Mhz. You can compromise between the two.

What is a Kernel?

It's the heart of the operating system (hence the name, like the kernel of a nut, the most important part of anything). It provides the environment for the phone's software to work, including access to the hardware. [Teppic74]

What is Nandroid Backup?

Nandroid backup is a backup that takes an entire snapshot of your phone as it is. This can be done from clockworkmod recovery, under the backup menu. It is not referred to as Nandroid in clockworkmod.

It can be restored at any time, over any ROM and will restore your phone to be EXACTLY as it was when the backup was taken. Always take this backup before flashing a ROM.
What other back up options have I got?

Titanium Backup is good. It backs up your applications, their data and settings plus system settings. Unlike Nandroid, it does not back up the ROM.

Settings between ROMS can differ, so if you over write new ROM settings with older settings backed up with titanium, some functionality can be lost. If you factory reset and it fixes it, try to restore as little as possible with titanium. Factory reset is the same as a wipe. titanium backs up what is wiped.

So what is all this about wiping? Do I need to?

Maybe. If you go from one stock ROM to a custom ROM, or one Custom ROM to another, the settings may not be compatible. You can wipe from ClockworkMod Recovery. - Wipe data/factory reset.

If the ROM is stuck in a boot loop for more that 10 minutes, you may have to back to recovery and do a wipe of the Data partition

Tell me more about Bricking?

A bricked phone is a dead phone. You can not recover it. It is very rare a true brick has happened. If you flash a dodgy ROM (by that I mean if you have a corrupt download or make a mistake), you can 98% of teh time recover it. Maybe with a Nandroid restore, an RUU or something.

During your rooting and flashing career, you will experience plenty of things you think are a brick. They are not. You just need to calm down, research, ask questions and get help.

Flashing corrupt or incorrect radio files is the most common form of permanent / true brick. As I said before, take care.

Can I still receive OTA updates?

No. Most custom ROMS block out this feature, but if you have rooted your existing rom, you may still get the option to install OTA. PLEASE DO NOT!!! You need to disable the setting that checks for updates. OTA updates often cannot be installed, but sometimes they appear to work. However this can lead to huge issues in the future so I beg you, please do not try to install one.

*thanks to everyone for your input in this, past or future.

 

Well now you have read the above, you should hopefully understand rooting and what to do.

Maybe but I dont know about it, but its easy so, no need for a video.

All the information above is specific, but I'll make you a step by step guide out of the already provided information anyway

1. Achieving root:

1.1

1.2 Open Visionary+ downloaded above. Look for the perm root option and apply it.

2. flashing rom

2.1

download ROM manager from Market

2.2

2.3 take backups of data

Titanium is available on the market. You may also want to backup sms / call logs. Personally I use mybackup pro

2.4 Open ROM manager and press the

2.4

via the ROM manager app

2.5 Take a

2.6

2.7

Browse to teh rom on SD card.

2.8

All this information I posted earlier for you. Reading the information should have given you all the information required to formulate this for yourself.

I'm sorry, I just can't help feeling I'm spoon feeding you a bit. If you havent understood what I have written, please read it again and again. It is not always easily absorbed but I am of the firm belief that you should understand exactly what it is you are doing and why before you actually do it.

Not only does it help you, but it helps people you turn to when you're in trouble if you understand

Its nothing to do with bricking your phone. Goldcard is a recovery option. If you have an operator / carrier branded handset, a goldcard will allow you to recover your handset using an unbranded RUU if no RUU exists for your carrier.

Although this is on a HTC Hero section, it is exactly the same.

Goldcard - Root Your HTC Hero

Guide and tool to make your sd card into a gold card

 

or see here:

Universal Android Temp Rooting Method (Visionary Method) (Updated 12.01.10) | TheUnlockr

 

Dont worry

If you flash a custom rom, you may need to download an RUU (Rom Upgrade Utility) for your DHD and that will return completely to stock.

If you don't flash a custom recovery and stick with the rom manager method, I am unsure if you can just restore a backup of your original rom and then remove root using visionary. Anyone tried this?

Unfortuantely I have not got a DHD so I can't test that

Some custom roms have custom kernels which can be overclocked, obtaining better performance and more efficient with processes which indeed can improve emulation.

For example, i run a vanilla custom ROM, overclocked and I can run PSX4droid much better than on my stock rom. even rebooting and force closing any apps running would still not perform well before. Now its fine whenever I run it.

Goldcards may well be universal but I havent tried it myself. The goldcard uses the CID of the SD card itself and is apparently not device specific, but I would still be weary of trusting that information until I had tested it myself (which I have not been able to).

Hope this helps a little, although its not fully answering all your questions.

 

Here's a video I found which seems very clear but doesn't do the gold card but ive found it very useful, i think things become a lot clearer what people have said after watching it.

http://www.youtube.com/watch?v=AkbmKLCkDWg&feature=related

Is it best not to use rom manager then? If you dont use rom manager what is the other method? This is the rom i was thinking of using:

[ROM] Android Revolution HD 2.0.11 | High Quality & Performance | OC | Sense/no-Sense - xda-developers

 

For the standard desire (that I have) our rooting method replaces the standard HTC recovery with Clockwork. It is better (IMHO) than using ROM manager (another level of software and hardware to go wrong).

Currently I don't think there is an alternative to RM on the HD, but I bet its just a matter of time.

 

Haha. Man, that thread is 12541 posts over 1255 pages! Suffice to say, the issues mentioned early on in the thread probably wont exist. Also, everyone gets different issues with the same roms so you just have to try it.

Do a backup via rom manager / recovery before you flash the rom and you can always restore it later. Give it a go.

 

All very helpful.
Thank you.
Tommaso

 

this might seem really daft but how long does it take to root your phone? I got the visionary+ software and tried temp root. it tells me it's attempting to root but doesnt seem to be up to much. does the process take a while or is it playing games with me?

 

Jungle are you on a build number below 1.72 if not it wont work and you will have to downgrade join xda theres loads of info and tuts on there that make life easy. You should always temproot before permroot as this is a safeguard as such.

 

hey snow, so if my build number says 1.32.178.5 then its all good to go ahead with root? just want to double check cos im noob. thanks for the help.