Just got my hands on a new Alienware 17 R5 and would like to make a few small tweaks to the BIOS. Successfully dumped, modded and ready to flash but getting the dreaded security error 18 in afuwin gui and CLI.

Short of a hardware programmer has a way around this version of security been found? I’ve read about afuwin SE with /GAN but it seems like thats for Aptio VI?

Anything I’m missing?

Much appreciated!

AFU DOS as you mentioned, or Intel FPT (use -savemac switch). Might as well pickup a programmer anyway, just in case you need to recover, they're only $3 + $3 for jumper cable

What is CLI?

I'd go ahead and pickup a CH341A flash programmer, they're cheap usually only $2.50-$4
https://www.ebay.com/itm/263458010112 - Choose "Blue" model

I assume your BIOS is soldered to the board, grab one of these too
https://www.ebay.com/itm/263708580560

Upload a copy of your modified BIOS, and link me w/ the original, maybe error is not security issue but problem with the BIOS mod.