OS X Mavericks
Boot Camp Assistant
1. Open Terminal and paste the command below, this will copy Info.plist to Desktop as a backup.
sudo cp /Applications/Utilities/Boot\ Camp\ Assistant.app/Contents/Info.plist Desktop/Info.plist.bak
2. Again in Terminal paste the command below, It will open Info.plist. Now move down and Add your BootRom Version under “DARequiredROMVersions” at Top of the List.
sudo nano /Applications/Utilities/Boot\ Camp\ Assistant.app/Contents/Info.plist
3. move Down again, find “PreUSBBootSupportedModels” and delete “Pre” from a word also add your Model Identifier at Top of the List.
4. now Save and Exit Terminal by Pressing “control + x” then ” Y ” and “enter”
5. now I assume that you have already installed Xcode, If not Download and Install it now for further steps or else you will get error.
6. After Xcode is installed open Terminal again and paste the command below:
sudo codesign -f -s - /Applications/Utilities/Boot\ Camp\ Assistant.app/Contents/MacOS/Boot\ Camp\ Assistant
7. Done, now You can install Windows using USB Flash Drive.
Untested with OS X versions earlier than 10.9 and also OS X 10.10 Yosemite Beta, but will update when a test is done.