Is there anyway to remove copyright data from a media file. E.g. if it ask for a username and password is there anyway to make the video not ask for it. Or away to re-encode it without the copyright?
If you have the username and pass, then yes. There are some apps released by a Japanese programmer that can dump the key from memory and then create a real wmv file or something like that.
'Tis no myth for sure. I have the apps at home, but no protected wmv files. So I never actually tried it. You might find this doom9 thread useful.