Sorry, I can't believe I didn't realize it was trying to add the unzipped folder back onto the CD - duh!
Must have had a "senior moment" there lol!
OK, I unzipped to the desktop and the unzipped folder is saying empty, even though when I tried the 2nd time in the video by unzipping in a new window, it did show all the files listed.
The seller has got back to me and said he'll let me download them if I have any more trouble.
Thanks for your help guys