[Abcdefg]

Use your Windows file browser and see if the CD contains files named with the MP3 extension

[kizzdogg]

Make sure you create the CD as an 'audio' CD and not a 'data' CD.

[arasina]

You have to make sure you format the CD for music and not just data or it won't work outside your computer. You may want to check to see how you formatted it.

[John Jorsett]

To play in ordinary audio CD players, CDs have to be burned specifically as an audio CD. Otherwise, you're just putting files on the CD in a format that the player won't understand. Whatever burner software you're using should have a "make audio CD" feature. Personally, I use the Nero CD burning software to make my audio (and other) CDs. I think they have a free trial that you can download from their site.

[paudio]

It seems you need to have another new CD and do it again correctly.

[kingu]

The other thing you need to do is to make sure you 'finalize' the CD (an option on Nero, others handle it as being a 'multisession cd') Most car stereos will not play a CD that is not 'finalized'.