Good news! Yes, unfortunately the boot.wim file is in a sub-directory of the CD so I could not see that from the listing you gave earlier.
I'm really glad that you got it working. Did you double check to see if by some chance the ZIP file might still be in the trash can on the desktop? If it is there it would then be possible to determine whether the download or unzip action created the problem. I did use WinRar to unzip mine again and came up with the same good result again but that doesn't really prove how it came out for you.
This might also be of help to you on future problems of this nature.
It always feels good to find the solution to something like this. Good job!
I have a bad habit to press "Shift+Delete" to delete files I don't need. So I can't find the .ZIP file again.
But now my computer can boot from my USB device. That's enough.
You know, there's always something you don't know why. For example, last year, my computer need at least 10 minutes to start and the pagefile took at least 1G. I used several anti-virus to scan, but fonud nothing. I tried several methods and ask some friends. None of the methods could solve the problem. At last, I have to fomat my disk and reinstall the system.
I hope symantec can provide all softwares' hash checksum, so that users could find where the problem is much easily.