Well, I called the dir "123" because it doesn't matter how I call it, I tried also Win7x64 and other, still the same error. Why .iso? I extracted the .iso file to get the folders which are needed for 7Customizer like "boot" ; "efi" ; "sources" etc. The folder is on C: and 5GB should be enought, I have just a 40GB hardisk (C:), and I can't delete more, but I think thats not the problem.