I'd like to know how Windows XP, Vista and 7 handle files without a file extension. I'd test it myself, but I don't have access to a Windows machine currently.
To my knowledge, Windows XP throws up over files with no extension, while Windows Vista an 7 are still incapable of reading the magic bytes to discern the MIME type, so the file is opened with the correct extension. Am I correct, or does Windows handle MIME types properly now?