You must have an unlocked bootloader for your device to root. Your device has HBOOT. Go to
HTCdev - Unlock Bootloader for instructions on how to do that and register. After unlocking your HBOOT, you need to "root" it or get SuperUser on your phone. I used 4ext, for me the most simple.
You need to download a couple of things. An
HTC Driver compatible with your device, android sdk for adb(just google it), a
recovery.img for 4ext, and the
SuperUser zip file. Make sure to uninstall HTC Sync on your PC if you have it.
Before doing anything, place the SuperUser file onto your sdcard in your phone. Connect your phone to your labtop and make sure usb debugging is enabled in settings, under development options. Make sure it is being charged only, not the disk drive. After downloading the recovery.img file and sdk-tools, put the recovery.img file with the sdk-tools. Make sure if it isn't named recovery.img, rename it that. Then, do shift+right click and press open command prompt here. To check if your device is connected type:
adb devices
Something should come up. Then type:
adb push recovery.img /sdcard/
Then type:
adb reboot bootloader
This will put it into bootloader. To do it manually, turn off the phone, and press volume and power (volume first). Then type:
fastboot flash recovery recovery.img
This will flash the recovery.img on to the phone. Then type:
adb reboot recovery
If that doesn't work, use the volume up/down buttons and power(to select) to press recovery. Now that 4ext recovery is flashed on, tap install from sdcard and "toggle script asserts." Then select choose zip from sdcard and select the superuser file that you put on your sdcard before. Now reboot.
Congrats! You don't have s-off but have root access and you can flash custom roms.
Please thank^^^^your Welcome.