I Am On Orange [2.73.61.66 Firmware] & I Cant Use Any Instant Rooting Methods
With the 2.73.61.66 ROM you can't use instant Root. The solution is very simple. You must downgrade to the 2.73.61.5 Orange ROM. Then you can use the instant root method.
Here is what you have to do:-
1) Download the ROM from the this
link from HTC.
2) Run the download. Follow the instructions.
3) Read this
thread and follow the instructions depending on what you want to do. e.g. Root or install a Custom ROM.
To sum up what you are going to do / have done.
You have downgraded your Orange ROM from 2.73.61.66 (latest) to 2.73.61.5 (old) in order to Root / install a custom ROM onto your phone.