The limitation with HTC's unlock method is that the boot partition is not flashable from recovery. This means that Kernels and ROM's with custom kernels must be flashed from Fastboot. It's easy, just see the 2nd post for the guide.
There have also been a couple reports of difficulty applying HTC's unlock to new phones that shipped with the updated software preloaded.
During the process, and after this output,
sending 'unlocktoken' (0 KB)... OKAY [ 0.152s] writing 'unlocktoken'... (bootloader) unlock token check successfully OKAY [ 0.006s] finished. total time: 0.159s
Thanks to lchupacabras for posting about this and his solution. Run the 2.08 RUU and then retry the HTC unlock, hopefully this works for everyone. I will do some more looking into this when I get a chance. My phone took a swin today and I'm awaiting a replacement, good thing i'm insured.
http://www.multiupload.com/09NOXKCUN0 Thanks lchupacabras for mirroring!
A short video of navigating from Unlocked Hboot 1.50 to TWRP Recovery
This is only for people stuck with HBOOT 1.50 and currently unable to root any other way. If you can't wait any longer to flash some ROM's then give this a shot. Please read the whole post before you start.
I'm posting this mostly because the info is on this site, but seems to be convoluted and spread out. I have gotten a few pm's from people asking for help with this after discussing it in other threads, so, here it is. I take no credit for any of these files, or any of the development. I'm just trying to get a good guide posted in one spot for people to use and learn from. I have tested this on my girls phone and everything is working great.
To start, you need to follow HTC's steps to unlock, so go here http://www.htcdev.com/bootloader/
It should be mentioned that HTC's unlock will factory reset ur phone. So if you have texts or anything else you want to backup, do it now.
Here are the required downloads to get you started with HTC's Unlock if you don't already have adb or HTC sync setup.
HTC Sync 3.0.5551
Java Runtime Environment (JRE)
If you tried these links over the past couple days, and they were bad, try again, they are re-hosted on mediafire for now, sorry for the trouble.
After you've followed their instructions, you can come back here to get your custom recovery and Superuser setup.
So, you got ur Bootloader unlocked via HTC, now, on your phone, go to menu > settings > applications > development and check the box net to usb debugging.
Now, here are the rest of ur required downloads for the next steps:
Thanks to Brandas for the above version of TWRP that works with HTC's unlock. He posted it in a thread last week, I just tested it and am posting it here.
Here is where he originally posted it, http://forum.xda-developers.com/show...&postcount=223
Take both the su.zip and recovery.img files and put them in your sdk tools folder.
Then, get in your command prompt from ur sdk tools folder.
Small tip, with windows 7, if you hold down the shift key and right click on ur sdk tools folder, the 4th option is to open a command window there. It's much easier then manually navigating there.
adb push recovery.img /sdcard/
adb push su-126.96.36.199.zip /sdcard/
adb reboot bootloader
fastboot flash recovery recovery.img
sending 'recovery' <5068 KB>... OKAY writing 'recovery'... OKAY finished. total time: 11.355s
Here you can pick "install zip" and then pick the "su-188.8.131.52.zip"
It will flash, the you can pick "back to main menu", then "reboot system now"
You will boot back up and have working Superuser. I have had no trouble with Titanium Backup, Root Explorer, Quick Boot or any other app that requires root. Before you do too much, it would be good to go back to recovery and do a Nandroid backup. Always best to get one ready before you start modding anything.
There is a limitation with HTC's unlock, recovery does not have permission to write to the boot partition, this is where the kernel goes. What this means is that you can't flash a kernel through the normal recovery. Which also means that you can't flash a ROM that requires a custom kernel. There are two ways that I know of to work around this. One is to just flash the kernel(boot.img) from fastboot, the other, and easier way is to boot recovery from fastboot and just do everything from there.
Please see 2nd post for ROM and Kernel flashing instructions