use these drivers
http ://d-h.st/v0p (for windows 7 & 8)
and check again usb debugging mode
use usb 2.0 ports
also make sure to be in fastboot usb screen
best wishes
Thanks rzr86. I tried those drivers but they don't seem to make any difference.
I've definitely got USB debugging on and am using USB 2.0 ports.
I believe I'm on the correct fastboot usb screen because if I unplug the USB cable, it actually shows FASTBOOT (higlighted in red) and when I plug the cable back in, it changes to FASTBOOT USB (highlighted in red).
Unfortunately the issue persists.
I took it a step further and tried this on yet another Windows 7 machine. I verified that I had the Android SDK installed ...and the drivers (under device Manager --> Android USB Devices --> My HTC) and it pointed to the drivers I pulled down from the link you sent me. Same issue on this machine as well.
So now I've tried it on 3 machines and all of them give the same error.
One other observation. If I unplug the phone from USB and then click on "Flash Recovery", I still get the device not found command prompt window....but then the next command prompt window shows < waiting for device >. This tells me that the tool does seem to detect the phone.
Normally if the USB cable is connected, it appears to flash the phone (on the command prompt) and shows these messages:
sending 'recovery' (6348 KB)...
OKAY [ 1.591s]
writing 'recovery'...
OKAY [ 9.239s]
finished. total time: 10.833s
However nothing actually happens on the phone.
Any advice would be appreciated!