I was wondering if you know of a way of creating a Windows 7 USB installation disk on Mac OS.
Here are the steps to be performed on a Mac to create a Windows 7 USB Bootable Installation Drive.
Open a Terminal (under Utilities)
diskutil listand determine the device node assigned to your flash media (e.g.,
diskutil unmountDisk /dev/diskN(replace
Nwith the disk number from the last command; in the previous example,
Nwould be 2)
sudo dd if=/path/to/downloaded.iso of=/dev/rdiskN bs=1m(replace
/path/to/downloaded.isowith the path to where the image file is located; for example,
diskutil eject /dev/diskNand remove your flash media when the command completes (this can take a few hours on slower drives)
sudo dd command executes for around 5 minutes, depends on the USB port and drive.)
If you have access to a different Windows box, try the tool from Microsoft here. There are also manual instructions here. I don't know of any way of making a windows-bootable drive natively in Mac OS X.
I've recently been through this. No matter what I did, I couldn't get my MacBook Pro (can't remember exactly how old it is, but it identifies as "MacBook Pro 3,1") to boot a Windows install disk off anything except the internal SuperDrive, which unfortunately is broken. I tried more things than I can remember, including external DVD drive, USB key, USB hard drive, Firewire hard drive, EFI bootloaders, etc etc etc.
In the end I managed a hack using a trial version of Parallels Desktop - instructions here. If you have a different model Mac to mine, you might find rEFIt helpful - it's an EFI loader that you can run either from your hard drive or a USB key that should hopefully make the experience of booting into the windows install a bit easier...