Verify if the drive is able to read discs. If the drive is unable to read discs, refer to the Dell knowledgebase article Optical Drive is unable to read discs.
If you are using a recordable ® or rewritable (RW) disc that was written on another computer, make sure that the disc is able to playback on the computer that was used to burn/record it.
Verify that the type of disc you are using is compatible with the drive that is installed on your computer. Refer to the Dell knowledgebase article Guide to Optical Disk Drives and Optical Discs.
If you are using a recordable ® or rewritable (RW) disc, verify that the disc burning/writing session was closed correctly. Refer to the User Manual of the disc recording software that you are using.
Try different brands of recordable ® or rewritable (RW) disc.