Microsoft → W7 64 bit not playing .cda audio files

We've got a relatively new Windows 7 64bit install on our laptop that won't play .cda audio files. The standard Windows Media Player 12 that comes with W7 is installed. Windows is updated currently. Windows can see the .cda audio file on the CD in the Optical drive, it just won't play it. When we attempt to play the .cda file, Windows plays one of the stock music programs that comes with W7 instead.

This is all very curious as we've still got XP installed on our old laptop. XP plays the .cda audio file with the XP version of WMP just fine.

Any tips or advice on how to solve this problem in Windows 7?

If it makes any difference, the .cda is a self recorded file and not a commercial CD.

Also note that there is no audio or video player on the W7 laptop other than WMP and WMC, neither of which will play the .cda audio file.

Interesting update:

The same version of Windows 7 64bit that is installed on our laptop that is not playing .cda audio files is playing the .cda audio file just fine on our desktop computer.

Both installs of Windows 7 are configured the same way. Neither have any other media players installed, but one plays .cda audio files while the other does not.

Why's that?

Start chasing down the association for that type.

Start from .cda in HKEY_CLASSES_ROOT in the registry.

That should point to something like WMP11.AssocFile.CDA which you should look up in the same place in the registry.

Compare known-good and bad systems.

Look at the commands for play and open.

Thanks got it.

"got it" as in you found the problem, or "got it" as in you comprehend the instructions?

if the former, what was it?

It is both.

Got that your instructions are understood and that following them solved the problem.

Comparing the two systems revealed that the Shell Hardware Detection service was Enabled/"Automatic" on the desktop system that would play the .CDA audio files. That service was not enabled on the laptop system that wasn't playing the .CDA audio files from the optical drive.

On XP it has been my experience that it doesn't matter whether the Shell Hardware Detection service is enabled or not. However, on our laptop version of W7 (Home Premium 64bit) it appears that windows 7 won't play the audio files until the service is enabled.

That seems strange since W7 can see the files even if the service is disabled, although W7 doesn't play the audio tracks until the Shell Hardware service is turned "ON". At least that's the way it works on our laptop when using Windows Media Player.

Hence, comparing the two systems as suggested and enabling the Shell Hardware Detection service on the laptop version of W7 solved the problem.

The file system driver will see what's on the disc regardless.

The Shell Hardware Detection service apparently determines what user-mode components are going to do with what's on the disc. I would guess that autoplay got cleaned up, since it was a little confusing in earlier versions (XP?) and this is a consequence of that.

For my own curiosity - without the service running, if you actually opened Media Player and selected the CD drive, or a track on it, then it played the wrong thing? Odd...

Without the Shell Hardware Detection Service running Window Media Player could not see the Optical Drive and therefore could not open or play the .cda audio files that were on the CD. Likewise if I went to the Optical Drive from "My Computer" and attempted to open them manually they still would not play. What would happen is that when I attempted to open the files manually Windows Media Player would open and would play one of the stock audio files that comes with Windows 7 rather than playing any of the audio files from the CD. All that got cleared up when the Shell Hardware Detection service was enabled and started. To prevent the problem from reoccurring on the laptop I sent the service to Automatic start and enabled it.

As to why the Shell Hardware Detection service was not enabled to begin with, I don't know the answer to that. The laptop was a relatively recent purchase. It came preloaded with Windows 7 64 bit and until now I had not noticed that it was in any way configured differently than our desktop which is also running Windows 7 64 bit.

Bottom line is thank you for your help. I understood your recommendations. They worked just fine.