Hi,
I am trying to modify a BIOS of a Chinese development board based on the Intel Z3735G CPU in order to install W10. The development board was designed to run Android 4.4.1 and was delivered with a fully locked BIOS. After reading many posts published in this forum I have managed to unlock access to the “Advanced” menu as well as remove the “Grayout if” from the options related to the “BOM”. The problem I currently have is that no matter what option you select in the submenus, it always returns to “Android / BOM2.1”. Is there anything you haven’t read in the forum about these options?
Menu IMG → https://drive.google.com/open?id=1E-FKF-…CVLAoNndDmEVnsk
I attach the dumped BIOS with an external programmer as well as the modified BIOS to display the options in the menu.
(edit)Dumped Bios → https://drive.google.com/open?id=1dlncRJ…GQZyBepNHuvDB8l
Modded/Unlocked Bios → https://drive.google.com/open?id=1lvcnns…yqr5XK0UnfIglkM
@Retloldin - How does the "always returns to “Android / BOM2.1"” happen? Right when you select the other, or on reboot?
Is the dumped BIOS above, stock/untouched by you? And, is the modded/unlock BIOS a programmer dump as well?
If the above is not stock BIOS untouched dump, please flash stock BIOS using stock method (not programmer) and send me dump of that (or send me your first programmer dump of unmodified BIOS)
Main thing I’m requesting there is a stock unmodified properly flashed BIOS >> programmer dump (so all your NVRAM and system details are in place, and so nothing lost when you program back)
Hi @Lost_N_BIOS , thank you very much for such a quick response!
Sorry I did not explain clearly the details of what happens when I select something in the BOM options:
After selecting any item other than "Android / BOM2.1" the BIOS needs to be saved and restarted to boot any HDD. After the restart the device tries to boot and then a screen with a message returning to the "Android / BOM2.1" configuration
The first dump was done before making any modifications to the BIOS, but I can get another dump from a stock board. Luckily (or unfortunately) we have a lot of development boards with the same configuration and BIOS.
If I have forgotten to upload something or I need to explain in more detail some step that I have done, let me know!
You’re welcome. So, that sounds like your changes have been done correctly, since you can save and that change is applied properly.
It sounds like that BIOS may not have the Windows BOM in there. Generally with BIOS I’ve seen like this, there is two separate branches of BIOS, you need to get the windows one (unless you had the ES one, ready for either or Dev mod)<br />Did you have a windows drive connected to the board on reboot? It shouldn’t matter, just curious. Odd that it would auto-reset to Android HDD there or not it should remain what you set it at, unless the Windows BOM is not in there
You’re comment here, contradicts itself >> The first dump was done before making any modifications to the BIOS, but I can get another dump from a stock board. << Please clarify, first part negates the last, so why would the latter be needed?
So, these are Dev boards? If yes, can’t you set Dev mode and install windows? I just want to look at a stock untouched BIOS, have not looked at any here yet, still awaiting clarification.
Hi again @Lost_N_BIOS !
At boot time after the configuration change I had W10 x64 installation disk. The HDD was deleted so it didn’t contain anything about Android.
What I was trying to say with that message was that I have access to more boards with the same BIOS in case it was necessary to perform another dump. I apologize that the message was contradictory, I see that I need to read my messages before posting.
Unfortunately I do not have access to any development BIOS or a version for Windows, so I tried to make the mod to the BIOS that the boards had.
I have made a dump of a board that was never used with an external programmer to be 100% sure that it has not been modified.
Clean Bios -> https://drive.google.com/open?id=1dlncRJ…GQZyBepNHuvDB8l
Thanks again for your time!
HDD “Deleted” what does that mean, unless the disk was “RAW” then it could still have some partition (or data in HPA) there or other android stuff windows wouldn’t see.
I gotcha now, thanks for clarifying. When I said “Set Dev” mode, I meant right there at the bottom of Android/Windows choices there is a "Dev Mode"
Thanks for untouched dump, I will check it out as time permits! 
Does this board have an eMMC drive? If yes, do you have rework station so you can remove?
Did you set Pre-OS to Windows too, at same time as the one on top you showed in image? And the one under that one too, OS/BOM Selection, so did you set all three to windows?