It took me a while to find out how to boot from USB on older HP Elite notebooks. HP8460p, 8470p and most probably others too. It needs to be pointed directly to efi file in bootable USB.
Brooo u r the best i can't describe how thankful I am! It WORKED! Thanks man you deserve all the support on this planet! Keept up the great work! Big up
also check your boot order list in the bios and try setting usb as the first in the boot order list, you can change it back after you restart from recovery
right now I hate microsoft more, their windows repair bootable media was completely USELESS!!! none of the recovery options worked, not even command prompt, or system restore