Για να δουλεψει το UEFI απο οσο ξερω αν δεν εχεις φορματ τον δισκο σε GPT δεν γινετε.
https://docs.microsoft.com/en-us/win...artition-style

Why should I convert my drive?
Many PCs now include the ability to use the UEFI version of BIOS, which can speed up boot and shutdown times and can provide additional security advantages.