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 