Click on "Computer" or "My Computer" and see what the optical drive is called. That will tell you what media it will accept.
For instance if it says DVD RW then it can read or burn CDs or DVDs. If it says DVD-ROM it probably can only play CDs or DVDs (but might be able to burn CD-Rs). It it says CD-RW then it can read and write CDs. If it says CD-ROM it can only read CDs.