Boot camp/ Windows 7/ No create disk option?

Hi,

I've tried everything i've read online to try and reappear this specific option as the boot camp i have installed doesn't let that option appear.

I've tried going through textedit and edit the .plist option but i don't have permission. I've tried the get info way to make the permission to read and write, it says that it is on that option for my user and it still says that the file is locked. I've completely gave up and reading loads of options as for most users the permission thing works but it just isn't changing for my iMac. I saw that you could change it through terminal but i have no idea how to use the coding on there so i haven't touched that program yet.

Can anyone help me, it will be greatly appreciated?

Thanks, Jack