I ran into the same thing this morning. My board is DZ77BH-55k, but the confusion is the same.
I tried the first one first, the EB.EXE one. The computer shutdown and rebooted quickly into Win7. I got the message that the update failed. I checked and I still had the old BIOS.
Then I tried the second file (the WINPE64 one) and I read the instructions. It said to kill all other programs before beginning. I did so and it worked. It shut down, then I got a screen telling me of all the things it was installing. This took several minutes. Then it rebooted Win7. Mission success.
I don't know if killing the other programs first made it work. I would guess using the second file made it work. Any way it worked and I didn't screw up the computer.
My suggestion is use the second one and kill any other programs first.