Adb commands only work when you're booted in the rom or recovery***** Fastboot commands only work when youre in bootloader
Here is a few simple things you can try:
*Try a different recovery.
*Try a different usb data cable.
*Try a different computer.
and this ..a little more time consuming..
*Try this http://forum.xda-developers.com/show....php?t=2588979 (obviously delete previous adb/htc sync/drivers etc)
If running windows 8 or above there is a fix in the above link...just read!
*Revert back to windows 7.
*Download “Ubuntu” and run on a livecd (https://help.ubuntu.com/community/LiveCD) then connect phone and do what you have to do.
*last resort look into things like this : https://play.google.com/store/apps/d....wifiadb&hl=en
***If anyone has another solution that works i will update the above****