Itunes and Napster to USB?

Pross
Pross Posts: 43,181
edited June 2011 in The bottom bracket
I'm trying to copy all my music to USB to play through tbe USB drive on my car (Alfa blue & me). Most of my files are unprotected mp3 files but I also have DRM protected itunes files and napster files. Can I just copy these onto the USB stick and play them or do I have to go through some method to re.move the DRM before copying them? I know there are plenty of techy types on here so would be grateful for your help in basic layman language. Cheers.