I'm guessing your computer is a PC and that it has one DVD/CD drive. If this is the case, you'll need to rip the CD first with a
CD ripper . Be careful when you load any free program because they like to try to add all kinds of junk that you don't want or need.
Rip the CD to MP3. Put in a new CD in your drive. The computer will see it and ask you what you want to do. Find something that says, "Make a music CD" or somesuch. (I'm guessing that the CD is a music CD.) Drag all the MP3s you just made into the box (or add them however it suggests) and push "go".