Thank you for contacting Intel Communities.
I understand you want to customize the splash screen on your Intel® Desktop Board.
As Al Hil mentioned, this can be done with the https://downloadcenter.intel.com/download/26307/NUCs-Intel-Integrator-Toolkit Intel® Integrator Toolkit; however, I am not sure if it will work with an older board.
You can see the readme at https://downloadmirror.intel.com/26307/eng/integrator-toolkit-6.1.6-readme.pdf Intel® Integrator Toolkit - Version 6.1.6 Readme
I hope this helps.