they're on the phone if you connect it to your computer you'll see them. It also has a qik pc app on it. A few nice surprises.
I think the tether drivers will work fine, because all you need is for the system to detect the phone.
Here you go: http://www.htc.com/us/support/t-mobile-mytouch-4g/downloads/
The driver on the sd card is the same as the one on the HTC website. What exactly are you trying to do?