Metabolix has written HackBGRT, a tool that changes the Windows boot logo on UEFI systems. It works on Intel 64-bit UEFI systems, with Secure Boot disabled.
“HackBGRT is intended as a boot logo changer for UEFI-based Windows systems. When booting on a UEFI-based computer, Windows may show a vendor-defined logo which is stored on the UEFI firmware in a section called Boot Graphics Resource Table (BGRT). It’s usually very difficult to change the image permamently, but a custom UEFI application may be used to overwrite it during the boot. HackBGRT does exactly that. Important: If you mess up the installation, your system may become unbootable! Create a rescue disk before use. This software comes with no warranty. Use at your own risk.” […]
Firmware Security 
How to change boot logo to windows 10 32 bit os?
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Hello,
I manually installed Windows 8.1 on an iMac 14.2, it’s booting with Apple EFI.
After some reboots the bootscreen only shows spinnings dots : No windows bootlogo anymore.
Can you tell me if hackbgrt may work on Apple efi… I think the efi boot try to show the motherboad logo… but apple didn’t put one in its efi. I think My bgrt doesn’t contain any logo, that’s why my bootscreen is only showing spinning dots. I also don’t know how to check that…
Thank you
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