BIOS update hung at 86%, what now?

just built a new system with ASRock Z170M Extreme4 mobo. powered up, all looked nice in BIOS. i had heard that it was best to update BIOS asap on a new system.

connected ethernet, started internet flash, download of BIOS 1.70 completed, BIOS update began, got up to 86% "Processing crashless feature ..." and it hung there. waited 30 minutes, nothing happening, had no choice (afaik) but to power down.

of course no joy on restart, BSOD and now dead in the water.

looked on the ASRock site, in the Download section, it says:
"If the Flash Memory Writer utility was not able to successfully update a complete BIOS file, your system may not be able to boot up. If this happens, your system will need service."

is that really it? there's nothing i can do?

please advise.

thank you for the reply, good info and a couple things there i'll follow up on. thanks again.

as it happens i found another -- more direct -- solution to my problem. poking around i saw it suggested that for recent generation ASRock boards that do not have A/B BIOS control one should __try__ the following (no guarantees):

- clear CMOS using the 10-minute time-out + jumper approach .
- format a USB key with FAT32.
- copy the BIOS of choice to the USB key.
- reboot with the USB key in place.
- cross fingers and wait, "if you're lucky the firmware will load from the USB key".

that's what i tried and it worked exactly as described. there was a considerable delay between the time i powered up and the point at which something came up on screen -- the BIOS loading from the USB -- but it eventually did its thing and i was soon back in business. minutes later my OS was loaded -- fyi, linux -- and i was happily booting from disk like a real person.

my other ASRock board is a Z97 Extreme6 and it does have A/B BIOS control which has got me out of trouble a couple times. i guess i just assumed all their recent boards had it and i never checked before getting this new board. one lesson learned today: i'll NEVER again buy a mobo that doesn't have some version of A/B BIOS control, it ain't worth the headaches.

i ran across an interesting post that opened my eyes regarding the issue of BIOS recovery as handled by the different board manufacturers. in BIOS recovery options by manufacturer the guy says of ASRock:

Dual BIOS - Only on high end boards, double DIP sockets. BIOS recovery - High end boards have dual BIOS. Nothing for the low end boards except replacing the chip. BIOS socketed - Yes You gotta send off for a new chip if you wreck your Asrock single chip BIOS.

he goes on to provide a similar summary for Asus, Gigabyte and MSI. interesting stuff! i'll certainly be limiting my future ASRock purchases to the higher-end, dual BIOS boards. and i'll be taking Gigabyte motherboards a little more seriously:

Dual BIOS - Yes, on all boards BIOS recovery - Automatically switches to the 2nd BIOS when the first  one is messed up. High end boards may have a manual switch like the MSI  boards. BIOS socketed - No, soldered.