Recently, I was playing with Nokia N91 and Napster on Windows Media Player (WMP). Nokia N91 is a music phone from Nokia that can hold up to 4 GB music files. Napster is one of the largest online music store. It sells songs protected with WMDRM (Windows Media Digital Rights Management) technology from Microsoft.

OK… I bought some songs from Napster and then synchronize them to my Nokia N91. So far so good. Everything went smoothly.

At some point of time, I had to reset the phone to the default factory settings (using *#7370* key combination). Guess what, after I did that, I couldn’t synchronize my songs any more. I got the message from WMP, “A problem has occurred in obtaining the device’s certificate. Contact Microsoft product support”.

A problem has occured in obtaining the device certificate. Contact Microsoft product support.

That’s bad, isn’t it? The worse thing is that I am an engineer but I had no idea what to do. I am wondering what the end users will do if they hit the same problem.

After spending a couple of hours, finally I solved the problem. The solution is so simple: REFORMAT THE HARD DISK. Puihhh…

What’s really happening there? It seems after I reset to the factory settings, the WMDRM certificate on my device is invalid. After I reformat the hard disk, a new WMDRM certificate is generated.

Bonus links:

  • Why DRM is Great and Why DRM Sucks
  • DRM Thoughts from S60 blog - It is not really related to my post. However, Jouni highlighted an interesting point that we cannot buy digital contents for every possible digital player.