The motherboard is an ECS 945 GCT-D DTX format board with a single core Atom cpu and Intel chipset and has a hdd with XP installed. (Don't laugh. It's run 24/7 for 2 or 3 years or more, and draws 38 watts at the wall with a 1T WD Green.) I'm trying to install a new OS that can see 3T drives from a USB flash drive. I have tried every setting in the bios that I can, but it still stubbornly boots into XP. I've set all three boot options to boot from USB, set the hdd boot parameters from the hdd to the usb drive, and the last action finally stopped it from booting, but it still didn't boot to usb. I've used two different flash drives, with both x64 and x86 OS, and the latter has worked on another computer, so it's unlikely to be the problem.

I've had this issue in the distant past trying to get a motherboard to boot to an internal cd drive (at that time it was probably Win 98 on the hdd). I've been reluctant to wipe or format the partition on the hdd to clean it in order to give me a fallback. Can't wipe it as I usually would anyway because there is a larger partition on the hdd with files.

The bios settings for USB boot are written: IC USB Storage, with four options, SMC, CFC, MMC, MSC and I've tried all four. Also tried with APIC disabled which seems to involve ACPI. Bios is AMI. I suppose I should try flashing a bios update. The computer does have a floppy.

Anyone come across this issue and solved it?