Hello,
Thank you all for this discussion.
Enable UEFI in the BIOS was the solution for boot problems.
I have 2 pc's with Intel DZ68DB board.
With ESXi 4, booting after a PXE installation wasn't any problem.
When installing ESXi 5, the server didn't boot from the local disk. Entering the (bios) boot-menu, and choose booting from local disk, made the server boot from local disk, but without using the boot-menu, it did not.
Changing the UEFI option in the BIOS from disable to enable, solved my problem. It's booting ESXi 5 from local disk.
Kind regards,
Philip