I am having a similar issue on a P8Z77-V LK motherboard. I do not see the "PATA SS" option even though I added the nvme driver to the BIOS file (attached).
I am trying to get Windows 10 booting from an NVMe drive, it installed fine (I know nvme is connected right) but isn't showing up in the BIOS for booting.

I tried modding the latest BIOS from Asus but it wouldn't let me EZFlash for security reasons, at this point I flashed the official latest version just to be closer to my eventual goal. I then tried...

afuwinx64.exe latest.CAP
afuwinx64.exe latest(mod).ROM /GAN
 

and that gave me a file size mismatch, even though Windows shows the same file size! From there I pulled the existing ROM using...

afuwinx64.exe extraced.ROM /O
 

added the nvme driver and was able to successfully flash with...

afuwinx64.exe extracted(mod).rom /GAN
 

I am pretty sure I am doing everything according to the instructions. Last year I successfully modded a P8Z68-V LX and am booting Arch Linux with that fine. Does anyone have any suggestions I can try? Thank you

#### Update ####
I was able to get a modded BIOS installed using ASUS AI Suite. Thanks for the great guide and links!

Hi Fernando, yeah booting is working now and the PATA_SS device is showing!
Yes you are correct in your assessment. when i said afuwinx64 flashed, what I mean is the command ran without any error. I don't think it actually did anything in reality.
What I probably could have done to verify is pulled the bios, flashed a modded bios, then pulled the bios again and verify is the checksums were different between pulls.

Hi, first off thanks to Fernando and other contributors on this website! Cool to see a lot of people getting helped through their problems.

Sorry if I am beating a dead horse. Does anyone know if I can m.2 boot(NVMe) my ASRock P67 Extreme 4 Gen 3? It's UEFI... I've literally read a million times it's not possible, but I don't believe it. And if I can't, it's not difficult with a Z77 or Z68, correct? I do a decent amount of video editing. Trying to figure out what is (most likely) most logical to do. Would love to run a 500GB Evo+ on this 'ol thing.

@Fernando:
Thanks for your help. I'm a bit confused still -- you could't get the BIOS file extracted? Are you suggesting since all the later boards should be capable, this one should in theory be, too? Since I don't know exactly what I'm doing, and that it sounds like I'd have to try out different BIOS modules(i think), would you recommend buying a cheap Z68 or Z77, or even P67 which has been tested like the ASUS models, and then just following previously documented methods? sorry for all the questions, just trying to wrap my head around this.

EDIT by Fernando: Unneeded fully quoted post replaced by directly addressing to the author (to save space within this very voluminous thread).

thanks, still more to look into I guess. Might be worth trying, but it doesn't seem that big of a deal to switch over to a Z68 motherboard.

this is my UEFI BIOS menu:

https://www.youtube.com/watch?v=5KOVNP5K8Ks

thank you again

need help modding Bios
M5A99FX Pro R2.0

i get this error
after adding the file and saving the file "Saving secure capsule as unsigned"
when try to flash it i get this error " selected file is not a EFI BIOS!"

please advice....

Sir,
here it is the the link for the stock bios
https://www.asus.com/us/Motherboards/M5A.../HelpDesk_BIOS/

this is my modded bios
this is one with using your "Guide for the usage of AMI's MMTool"
File name start with MMTool

i got this error during the process "Saving secure capsule as unsigned"
try to flash the file got this error "selected file is not a EFI BIOS!"

this one with using "Guide for the usage of the UEFIToo"
File name start with UEFIToo
try to flash this i got this error "Security verification failed"

new formatted fat 32 USB Drive.

Manufacture of the board is ASUS Model M5A99FX Pro R2.0

Hey. Great Forum. So much informatioin! Wish I had found it years ago.

ASUS P8Z77-V LX Can see NVMe from Win 8.1, 10 and Ubuntu 18.04, but no luck thus far adding NVMe support to the BIOS for booting. Using latest BIOS, 2501, modded with UEFITool adding NvmExpress Dxe_4, per guide, but no change in file size after saving. No issues flashing. Clearly I'm missing something.

Hey Ferando, Thanks for the welcome and your assistance!

Both versions of the BIOS are attached. I was/am suspect of the modded version as the file size is the same for both. I do not see any additions to the BOOT section of the BIOS, or anywhere else darn it. I flashed the BIOS with EZ Flash from within Win 10.

Cheers,
Reg (alias RAWEast)