OK, I created an EFI-only version of Windows setup per Force Windows 7 install DVD to do an EFI Boot - InsanelyMac Forum
But when I try to boot, the LED on the DVD flashes a few times, then nothing happens. My display is blank with a blinking cursor.
I suspect the problem is that this DVD won't boot because my system in not in pure EFI mode. There is a BIOS setting for "EFI Optimized Boot" - but the last time I tried setting that my system became a brick and I could not boot anything or even get back to the BIOS settings. I had to clear the CMOS in order to be able to get back to a working system. I'm working with Intel Technical support - but the dialog is slow because I only seem to get one response from them per day.
It's really a shame that Windows 7 cannot install/boot a GPT disk while the system is in BIOS mode. Is this some hard restriction about the BIOS, or is it that Microsoft have just not gotten around to supporting it?