Problem with tablet Intel to flash bios with custom logo

[Markosgo]

Hi. I have an Unusual 7W First tablet with Intel processor and it was running windows 8.1.
I updated it to windows 10, but in the splash screen it appears even in the logo powered by windows 8 ... so I decided to modify the image so that I put windows only.
I have managed to extract the rom with the latest version of "AMIBIOS_and_Aptio_AMI_Firmware_Update_Utility", remove the splash screen with "ChangeLogo_v5" and have edited it and left it to my liking.

I used "ChangeLogo_v5" to load the backup of the bios rom the new image, I have skipped a resolution size warning but I have read that it is normal and I have continued the process ... and I have skipped the following warning "Warning! Remplacing logos may invalidate secure flash signature, do you wish to continue?"
I can continue to log in to the logos. I have accepted and saved the new backup.

When I try to flash it with "AMIBIOS_and_Aptio_AMI_Firmware_Update_Utility" with Aptio V which is the one that corresponds to my tablet I find two options "afu and btg", I extract the rom with afu, so as I do not know where they differ i have always used afu , Because I have done the whole process with this method ...
18 - Error: Secure flash rom verify fail "... and there was no way to flash it.

I have read several issues that deal with this error, and I have found the program "Backup tools" and created the results file, I send it to you to have a visit
Https://www.sendspace.com/file/s3twkd
Inside I have included the new splash screen that I want to integrate.

I have also tested with another solution from another forum topic where they used "Universal BIOS Backup ToolKit 2.0", but it does not recognize the bios version, so I can not extract it.

Please, ask for help to help me create a modified rom with this splash screen and be able to flash it.

Greetings and thanks.