I am trying to install Windows 7 on my MacBook as a dual boot setup. I have a MacBook 7,1 running Mavericks. I have replaced the DVD drive with a SSD (now have 2 internal drives) so cannot use a windows CD to do the install. I have used the trick that alters the BootCamp info.plist file to allow me to create a bootable USB to do the install. So I have a bootable Windows 7 installer USB. I know this works because I can boot into it on another MacBook.
However, it turns out that my MacBook can't boot from USBs other than USBs containing a Mac OS. The BootCamp created USB (Windows 7 installer) does not appear at all on the grey boot sources screen (holding option at boot). I have tried rEFIt/rEFInd and they see that there is an OS on the USB but when it tries to boot it gives me a heap of errors saying that Mac can't boot "legacy" OSs from a USB.
To summarize: Its not a problem with corruption or incorrect formatting. I put the USB into another (newer) MacBook and can boot into it absolutely fine. This is a problem with my MacBook not being able to boot from USBs.
I need a way to boot from this USB even though the mac won't natively do it. Is there an alternative bootloader that I can install on my macbook to provide this USB booting functionality?