Tested on HP Elitebook 840 G3. You may also use this tool to change the logo to your own custom one.
Recently I acquired an used HP Elitebook 840 G3. Everything was fine with it, but it had a custom UEFI logo when starting the OS - it was branded by the company that owned this laptop before.
As it became my personal laptop I didn't want it to be branded by them and I tried to find a way to restore the original HP/Windows logo (it had the custom logo during POST and during the OS startup as well).