What is the size of the hard drive and how are the partitions arranged?
Does the disk have MBR partitions or GPT partitions?
What is the system and what is it's age (mainboard and BIOS revision)?
As an experiment, you could try deleting the second partition on the USB hard disk, just to see if an MBR boot option is then listed.
Does the disk have MBR partitions or GPT partitions?
What is the system and what is it's age (mainboard and BIOS revision)?
As an experiment, you could try deleting the second partition on the USB hard disk, just to see if an MBR boot option is then listed.