Microsoft has announced that it will be switching off the MSN Music license servers at the end of this summer, leaving millions of users with a potential headache and potentially unplayable MP3s.

Because the servers are used to authorise playback of MP3s purchased from Microsoft's now defunct MP3 store, users who have downloaded songs from the site will not be forced to commit to which computers they can play their DRM-protected tracks on in advance or lose them forever.

Forewarning from MSN

According to Ars Technica, an email from MSN general manager Rob Bennett has been sent to customers forewarning them of the planned switch off:

"As of August 31, 2008, we will no longer be able to support the retrieval of license keys for the songs you purchased from MSN Music or the authorization of additional computers," Bennett explains in the mail.

“If you attempt to transfer your songs to additional computers after August 31, 2008, those songs will not successfully play," he adds in a matter of fact way, clearly not in the least bit aware of the mass gnashing of teeth his message has just caused.

PlaysForSure license

Under the PlaysForSure license granted with MSN Music downloads, users are able to license and play the MP3 file on up to five computers. But of course, even with four credits left, it’s impossible for users to supply the details of a computer they don’t intend to purchase until after the switch off.

So, unless owners of the affected MP3s are prepared to keep their existing computers forever, the DRM-encoded music they’ve already paid good money for will eventually become unplayable.

Like we said, it’s just one more reason to be thankful that DRM is on the way out.