Knoppix is normally released as a ISO file that MUST be burnt "AS AN IMAGE" to a CD to make it bootable. Simply copying any set of files (or even a bootable ISO) to a disc (DVD rather than CD most recently) will not allow you to boot the resulting disk, you just end up with a disc with files on it but no boot structure. If a disc could be created that way, then I expect Klaus and others would do it, as convincing newcomers to burn the ISO file "AS AN IMAGE" is one of the more challenging things for a novice to overcome. If you want to be able to boot a disc you simply can't just copy files to it. So whoever gave you that information was wrong. Beyond that I don't know what he was trying to do or what he gave you, I suggest that you get back in touch with him.
However, you say that you got a zipped folder, but I have to question if you are sure that you were given a zipped folder of are you letting Windows hide file extensions from you and have you by chance really been given an ISO file? Many people have come here thinking they have a zip file but really have an ISO file and Windows is hiding the extension from them (and they foolishly don't turn that "feature" off). If you have an ISO file then follow the instructions for burning it "AS AN IMAGE" and you'll likely produce a bootable image.
I recommend Nero for this purpose, even the brief trial version. Windows 7 (and I suspect later versions) can burn an ISO into a bootable image but Windows doesn't let you do a low speed burn, and high speed burns have their own set of booting problems.