Boy, this thread had me scared!
Having had one DH77KC (BIOS v. 69) mysteriously deteriorate to power cycling without my intervention, I was quite upset by what I read here when memory voltage multiplier issues compelled me to upgrade the BIOS on the second, sooo...
As advised by an Intel tech help chat agent, I used the recovery BIOS method to upgrade in stages, from 69 to 100, then from 100 to 104, in the same session, first having stripped the machine down to 1 (8GB) stick of memory, no SATA devices, and with only keyboard, mouse, and monitor connected. I bought a 4GB USB flash drive for the purpose, since the board seemed unable to locate the .BIO image file on my nominally 8GB thumb drive.
Success! (Despite the warning noted below.*) The serious memory voltage multiplier problems of v.69 have been fixed, and there's a shiny new "Intel Visual BIOS" user interface.
Still, the firmware for this board still seems something of a work in progress. E.g., to see memory speed reported you must enter "Classic" mode, from which there doesn't seem to be a way of getting back into the new "Visual" UI except by restarting.
(Since Linux isn't supported on Intel's desktop boards, I won't mention that the ethernet device appears, to the Linux e1000e driver at least, either mismapped --as the memory voltage multiplier had been? -- or disabled even when "enabled". If it's a driver problem, it appears to be one that nobody else has reported.)
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* Note that it seems that on your first reboot (of, say, an OS LiveCD image) from a USB flash drive which happens to have a .BIO file remaining on the top level may show an alarming "BIOS flash update failed" message, and subsequent such boots may be recorded (without your seeing the screen message) in the BIOS events log -- even though no flash update has been attempted. The simple, inadvertent presence of a .BIO image on a USB drive seems to trigger the response.