Encrypted Cd?

Hi people,
a friend of mine asked me how to create a Cd which nobody else can read (I suppose that he wants to store there his personal private stuff).
I have not the lesser idea.
Can you suggest me something free? (or trial, shareware, etc).
I have Nero, but no idea if it can do it…
He does not need a NASA security, just something basic against common people too curious, nothing against hackers.
I thought that if it is possible to protect with a password a folder, he can put all inside this folder, and then put it in a cd, and nobody could open the folder without the right password.
Or he could make a rar file, with a password…
I guess that the operating systema of him and of the possible curios people will be XP…

Thanks! (:WAV)