What a nightmare! Wow, I haven't had an experience like this in 20 years. I'll be as brief as possible here in an attempt to help others…because I wouldn't have solved my problem without this community's and Intel's Tech Support on Labor Day, no less. Thanks to Yogesh, Tobias and Richard as well as the literally dozens and dozens support forum posters that had anything to say about BIOS recovery. Before I go on, I should say I've flashed BIOSs on hundreds of motherboards over the last 25 years and have had less than five actually fail on me (all various makes, models and manufacturers).
My issue was flashing BIOS on an Intel DH57DD from version 0601 to 0656 (skipping a version, though I don't think that’s relevant). My hardware includes; NVIDIA GeForce GTS 450, 8GB Kingston (4x2GB PC3-10700 DDR3), several Western Digital SATA drives, HP DVD1270, Logitech G15/G13 USB keyboards and a Microsoft USB mouse.
What went wrong: I used the Express BIOS update file as I had no previous issues with this method with other Intel motherboards. The flash didn't quite complete after 15-20 mins (process *should* take 2-5 mins according to the documentation). My symptoms were; the system would not boot completely, it continously rebooted, it showed no video and beep codes were <beep><beep>-<pause>-<beep><beep>. This according to other forum posters and Intel documentation indicates a video problem. Right! I had NO VIDEO !! (SUGGESTION to Intel: Add more documentation for those situations with no video). The following is a summary of a 14-18 hour effort to successfully recover my BIOS.
This is what worked for me: (this assumes you have another system capable of downloading files from the Internet and that system can write to a USB Flash drive. Let's call that system the Technician's system. Let's call the system you are trying to recover the BIOS on; the Target system).
PREPARATION (using the Technician's system)
RECOVERY (all on the Target system)
Your system should now be "recovered". It should be noted here, that I had to go back two BIOS versions to get my system bootable again. After which I did NOT attempt to flash BIOS again. However next time, I may try just the recovery process instead of the Express BIOS Update (through Windows). Other forum posters reported issues with running the BIOS update with NVIDA cards installed.
Hope that helps. Thanks again to Intel and all forum posters.