Ater placing my device into fastboot mode, I have tried flashing my downloaded TWRP file to my HTC One in Terminal using these instructions:
Now let's flash your downloaded TWRP file to your HTC One. Type one of the following commands into your terminal window, depending on which file you downloaded above.
For the International editions, type:
fastboot flash recovery Desktop/openrecovery-twrp-126.96.36.199-m8.img
However I get the following error:
command not found
any help would be most appreciated.