Pre-boot customization does not work for splash and login image (custom image) on Windows 8.1 and Windows 10 OS with UEFI enabled.
Pre-boot customization on UEFI systems is only supported to customize text and not images (.xpm files).
Symantec Corporation is committed to product quality and satisfied customers. Support has worked directly with Product Management and starting with Symantec Endpoint Encryption 11.1.3, customizing the preboot screen is now supported. To download this version, visit Fileconnect.