Booting MacBook with Windows USB Disk

[Radiating]

I'd like to boot my mac into windows bootcamp with a USB drive, but while holding down the option key and going into the system picker it doesn't show my USB drive as an option.

The partition is active, and bootable (it's a hard drive ripped from my old computer mounted on a USB interface).

My third party USB CD drive boots the windows CD just fine.

What can I do to get it working and booted?

 

[Weaselboy]

That won't work directly as the Mac uses EFI to boot. You might be able to get it working using Refit.

 

[LeeM]

i read something about windows restarting the usb ports during startup

 

[Radiating]

I was able to get it working by plugging in the USB drive when the system picker started. It would not work if the drive was plugged in before the computer started.

Other than that it booted just fine, except that it blue screened as soon as it tried to load windows due to incorrect drivers.