I tried to upload a couple of my songs from my iTunes playlist onto my movie, but I couldn't. A message then popped up saying that unless I downloaded a "codec" then I did not have the authorization to use that song, that I had already bought. Does anyone have any idea what the "codec" could be?
Did you buy the songs from the itunes store? I'm pretty sure that songs from the itunes store only work in itunes and on your ipod. but you can get around this by burning them to a cd then riping them back into itunes again. If the songs were originally ripped from cds its probably because they a .acc/m4a files so you'll have to change the settings to mp3 as windows movie maker only supports mp3/wma/wav(don't use wav it makes MASSIVE files or really crap sounding songs depending on the quality)