: If no PC is in visible range, the USB/DVD Download Tool won't do you much good - in that case, you'll have to work your way to the command line:

1. Open a Terminal window and run "diskutil list". Determine which device node matches your USB thumb drive (e.g. this could be "/dev/disk4").

2. Unmount this disk by typing in "diskutil unmountDisk /dev/diskX" (where X stands for the number of your USB drive -- in our example, it would be "diskutil unmountDisk /dev/disk4").

3. Type in "sudo dd if=/PATH/Windows7or8.iso of=/dev/diskX bs=1m". Make sure to replace the "/PATH/Windows7or8.iso" with the correct path of your Windows 7 or 8 ISO file and, again, replace the X with the drive number.

4. Done! Once the operation is complete, run the "diskutil eject /dev/diskX" command to eject the flash drive!