So you're not storing the ISO file, that is, .
So it's not a normal read-writable file system containing an ISO file.
ISO file or the compressed files.
Microsoft themselves offers ISO files of Windows for free on their website.
Those are not ISO files of Windows.
Those are ISO files of service pack updates for Windows.
It comes with an ISO file that needs to be written to a CD.
It can also burn multisession discs and ISO files.
So email and SpinRite's small ISO file came to the rescue.
Most of the Blu-ray player software can also play Blu-ray ISO files.