The rom flash is trickier than expected. You will need to actually go into the sd card for this. So...
Make sure you have the
Recovery Image and it is in AndroidSDK\Tools
Type exit until you get to the C:\AndroidSDK\Tools>_
Type this exactly: adb push recovery-RA-heroc-v1.6.2.img /sdcard/
Once that is finished it will say something like it did it and tell you it took 1 to 5 seconds.
Now it will be back to C:\AndroidSDK\Tools>_
Type adb shell
will get $ so type cd /sdcard/
will have $ again, type su
will have # so type this exactly flash_image recovery recovery-RA-heroc-v1.6.2.img
You know to press enter after every one I listed, this will repeat recovery-RA-heroc-v1.5.1.img if it worked if you get out of memory, reset phone and box and repeat the steps exactly.
When you think it worked: Power down phone. Power up holding volume down and End key. If you are rooted you will get a white screen with 3 options. One of those options is to press home for recovery, press it and you will either get the htc screen w green words or you will get a phone with an exclamation point. The ! is a sign that you don't have a recovery image installed correctly. The words is a great sign, continue with back up from nandroid. Oh and don't partition your sd card until you have backed it up!!
Last thing, I can't encourage backing up with Nandroid enough!! I've already used it 5 times!!
Edited to include 1.5.1 which was brought over by
Bradart in this thread So make sure to go by and thank him too.
Re-edited to include the 1.5.2 that I forgot about. I am running it, its mint. Thanks Athlet1c.
Added 1.6.2
Here is
1.2.3 Some people need it because straight to 1.5.2 can be bad on a first root.