Windows Media Player won't play music CDs

My computer used to play music CDs, but now won't. When I try, I get a message saying "Windows Media Player cannot play the file. The player might not support the file type or might not support the CODEC that was used to compress the file." These are commercially produced CDs, and they'll play on my car player. WMP will play other verbal audio recordings I've made, but won't play copies I've made of commercial CDs.

I've uninstalled a number of programs, and wonder if I might have deleted a file that was a shared file.
When I click on the Web Help button of the message, it just takes me to a general Windows 7 screen.

How can I find out if I'm missing the codec, and if so, how to find out what it is so I can download it?
I have an HP Pavillion Elite computer with Windows 7/64 Home Premium.
Any help will be greatly appreciated.

Thanks, John.
While I was awaiting a forum reply, I went online and found a codec download, so tried it. However, that didn't fix the WMP problem, so I changed the audio opening program to iTunes, and it works great. I like it a lot better than WMP because it shows all the songs on the disk, whereas WMP shows only what's playing at the moment.
Nevertheless, thanks for taking your time to send a suggestion.

Glad you were able to get sorted. I prefer iTunes myself since I'm using it on all my devices, some which are Apple. When I've had problems with WMP in the past, I usually just reset it and let it repopulate.

We will consider this issue closed.

You can use some third-party video conversion program to encode the files to Windows Media Player compatible audio codec such as wma/mp3/wav/cda/m4a