Rooting And Installing Custom ROM On UK HTC Desire
Here's my experience with flashing a custom ROM into my HTC Desire. My phone is the UK T-Mobile model which came with the stock Android 2.1 Eclair and HTC Sense. There are many in depth tutorials out there about rooting Android phones and installing ROMS (and this is not one of them) but I would have liked to read a basic overview of the process and someones experience with my exact hardware. So I'm writing this for you.
It's a two step process. Root the phone, then install a new ROM.
Root the HTC Desire
This is SO easy compared to how it used to be with the T-Mobile G1 in the early days of Android. Simply use Unrevoked to do it for you. (Unrevoked also works for various other models of Android phone such as Evo, Droid Incredible, Wildfire etc). Download it from http://unrevoked.com/. It involves installing a special driver on your computer that does the work rooting your HTC Desire over a USB cable, with the phone in USB debugging mode. It comes with all the instructions you need.
Now you have a rooted phone which will work the same but you will have Superuser Permissions in your apps menu, so you'll know it's worked. You can now run apps that need root permissions, such as Titanium Backup and various screenshot apps. Also, you will now have the Clockwork Mod recovery console available when you boot the phone if you hold down Volume Down key. This is where you install your new goodies, and you can also do a full backup of the phone to your SD card here. I did just that in case of disasters in the next step.
Install a custom ROM
I wanted to use Cyanogen MOD, having been very impressed with it on my old T-Mobile G1, but it wasn't clear whether the new Cyanogen ROM would work on the HTC Desire, so I went for LeeDroid's ROM instead which is a version of Android 2.2 Froyo with HTC Sense, so it looks (almost) the same as the original Desire ROM. I downloaded the required files from and followed the instructions on this page on XDA Developers. It involved installing two zips, the first being a radio update and the second the actual ROM itself. To do each, you simply plonk the zips into the root of your SD card, then choose to install them with the Clockwork MOD recovery console.
Installing a different ROM will wipe everything off your phone, so I backed up my apps with Titanium Backup in between steps 1 and 2 and restored them afterwards, and all my apps work perfectly, with all their settings intact.
Simple as that. So far, I've been really impressed with the new ROM. It hasn't crashed once and works as it should.
Good luck with yours!
Installing ROMS is even easier with ROM Manager. First, complete step 1 above, then install ROM Manager from the Android Market. Choose and install your new ROM from within the ROM Manager app itself.
My ROM of choice for the moment is DeFroST, which is available from within the ROM Manager app, or from this page here. I use this one because it's fast (overclocked), stable and bang up to date. It comes with its own app which you will find in the main menu, which allows you to easily install updates and MODs.