People trying to buy songs from Puretracks Inc.'s online music store after the company announced it is offering MP3 files without anti-copying measures complained Thursday that the files wouldn't play on some computers.

CBC and other media outletson Wednesdayreported Puretracks' announcement that it would immediately offer an initial catalogue of 50,000 songs in the MP3 file format devoid of digital rights management (DRM) restrictions.

DRM is a catch-all term for a broad range of technologies used by copyright owners to control how a piece of data, software or hardware can be used by others.

The measure is commonly used to restrict the ability to copy or transfer music or movie files such as those bought from sites like Apple Inc.'s iTunes Store or burned from a computer to a CD or DVD.

Readers of the popular blog Boing Boing complained that the songs use Windows Media DRM measures.

"It appears that all the tracks at this music store are toxic Windows DRM crippleware. Stay away — far away," Boing Boing editor Cory Doctorow wrote in a post to the blog Thursday after being alerted to the problem by readers.

Users of computers made by Apple Inc.were directed to a page on Puretracks' website that read, in part: "Our current music store uses Windows Media technology to play our music files. Unfortunately that means our songs are incompatible with your operating system. Furthermore, Apple's iTunes FairPlay system is currently not available to us for use with iPods."

The notice alsosaid Puretracks supports Internet Explorer versions 5.0 and higher on Windows operating system versions 98SE through XP.

A Puretracks spokesperson was notimmediately available for comment.