Using this bios now working fine booting a NVMe 1 TB via a PCI slot adaptor.
Uploaded the .ROM file to save some steps.
Only mod was adding the NVMe module.
Edit by Fernando: Thread moved into the "Already modded special BIOSes" Sub-Forum and title customzed
Q87M-E-ASUS-3801_MOD.zip (7.21 MB)
I can confirm that this Asus Q87M-E 3801 modified bios works but it changes your MAC address to 88:88:88:88:87:88, which apparently is a know bug on this type of bios.
You need to use the Intel Eeupdate.exe program to set the MAC address back to your original MAC address. There are lots of versions of Eeupdate.exe program for different chipsets. I used v5.30.10.00 which worked correctly.
Hi,
I just tried to flash te bios you provided but without success. The file file you provided uses a ROM extension - however the BIOS update utility wants a CAP file. Tried with another modded CAP file but managed only to provoke a BIOS error and had to flash back an official image.
I’m a total newbie regarding BIOS modding but can follow instructions 
To your knowledge is there a working CAP version of the Asus Q87M-E v3801 BIOS with added NVMe Support?
Thx for any help,
Matej
That is why its ROM and not CAP.
CAP mod will fail security and you have no USB BFB feature on that motherboard model, read the linked guide.
EDIT: Did you perform a safe keep backup of the bios, before any flash mod? You should as it contains motherboard/system own data.
Did you performed the mod from another user file or used another user file?
Retail/End user motherboards do not contain embedded MS KEY/Activation unless from specific OEM/Assembled systems. On old bios backup if exist such data, its there and if the mod was done from the backup file it should be there also.
No backups we cant do nothing…and theres plenty of ways of a working OS loses his activation on several user actions and hardware changes, you may think that you has a mb with PK and its just an hardware change…presuming only from my point of view.
Still besides MS PK theres a manual way to add SN and MAC to it.
MeatWar thanks – updated the BIOS (per instructions in the guide) and reset the MAC address. NVMe boot support works! However I have created a new problem for myself – the BIOS update deleted the embedded Windows Product Key or somehow messed up the Windows Activation… I guess there is no easy solution for this (new) problem 
I have an Asus Q87M-E motherboard. I have tried everything but I can’t seem to flash this BIOS. Every Asus tool needs .CAP but the file is .ROM and there is no way to convert it.