We have got a new computer Dell optiplex XE3.

The new computer doesn't have option to boot legacy from hard disk.

I can install SUSE from an USB-connected-external-DVD But when I tries to start boot the installed system it will not boot.

But a strange thing is that it is possible to boot from harddisk if I have the USB-connected-external-DVD connected when I boot.

Does anyone have a idea if it is possible to solve this system and still use SUSE11SP3?
Bios setting? Partitioning? UEFI settings?