Why not go on Youtube, use the Youtube Downloader, then download all the cinematics that you're missing?
Edit: I just did a quick search and found all the Diablo 1 and 2 cinematics on Youtube. They shouldn't be hard to find. Try using Google if they don't show for you.
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Edit: I just did a quick search and found all the Diablo 1 and 2 cinematics on Youtube. They shouldn't be hard to find. Try using Google if they don't show for you.