I've been wanting to get Windows 7 on my late 2006 iMac, but it won't recognize my USB stick when I hold alt at boot. Apparently, BootCamp uses MBR for Windows booting, and the 5,1 doesn't support booting in MBR when using a flash drive. Is there a way I can trick it into working? I don't have a USB DVD drive, and the internal one is borked.