Is converting a DVD to an ISO, and then burning that ISO onto another DVD exactly the same thing as copying all the files from one DVD to another? What about if instead of copying to another DVD, I copied to a USB flash drive (i.e. DVD > USB), would it still be the same thing as DVD > ISO > USB?
If they are the same, then why does Microsoft have a specific tool for copying the Windows 7 ISO onto a USB flash drive? Couldn't I use any tool that extracts an ISO and copy the resulting files onto a USB flash drive? Or if I had the original DVD, couldn't I copy the files from the DVD directly to the USB flash drive without bothering with Microsoft's utility at all?
Best Answer
The major advantage of an ISO is that burning it as an image preserves the bootloader, where extracting and burning the contents does not. The bootloader needs to go on a specific part of the CD/DVD/USB drive for it to be bootable. Just burning the contents does not do this.
The other advantage is that you can make a checksum of the entire ISO instead of each file it contains. That can be used to make sure that the download happened without error.