Hi roybad, and welcome to the VMware Communities!
What's the Linux distro you're installing inside the guest?
What do you mean by "the disk isn't EFI"? If the guest is partitioning the disk as MBR instead of the EFI-standard GPT, it might be that the guest OS is confused and isn't correctly installing for EFI. There are a few older Linuxes (Linuces?) which try to work with EFI, but don't quite get it right.
Cheers,
--
Darius