Microsoft loves DRM.

Digital Restrictions Management (DRM) are technology measures that restrict what people can do with their computers. DRM is built into the heart of Windows 7, and many Microsoft services push DRM on users. In some cases, Microsoft has added these restrictions at the behest of TV companies, Hollywood and the music industry. In other cases, Microsoft DRM goes way beyond these companies' demands, suggesting that Microsoft is using DRM simply to create lock-in. Whether Microsoft is merely a co-conspirator with big media companies or an advocate for DRM in their own right, the result for software users is the same...

The monomaniacal fear of big media companies is that people will share digital media with their friends, building a free public library of cultural works. Public libraries are wonderful institutions, and in a digital age they become almost miraculous: we can now provide universal access to human knowledge and culture—or at least anything that's been published—at little or no cost. The amazing thing is that it's almost automatic: once people can share freely with their friends over a global network, you get a digital public library. P2P networks are one example of a digital library, and the web is another. The value of these libraries to the public is historic and immeasurable. But media companies serve shareholders, not the public, and are therefore very ready to destroy in its infancy any public resource that might interfere with their profits. The personal computer is built from the ground up to make sharing information fast and easy, so for media companies to restrict sharing they need the full cooperation of software makers at the deepest level. Enter Microsoft.

In order to completely prevent sharing, media companies needed Microsoft to do two things:

• First, they had to make sure that any outgoing digital signal is just as locked down as the DRM'ed music or movie file. Otherwise you could simply play a video on your computer out to another device (like your digital camera) and press record. So Windows, when playing a file with DRM, needs to constantly check to make sure any connected device is cooperating with the DRM scheme. This anti-feature is called Protected Media Path. Microsoft introduced it with Vista, and it continues in Windows 7.

• Second, media companies needed Microsoft to keep other programs from observing the playback process and intercepting the audio and video in unencrypted form. After all, it is still your computer, and (as much as media companies hate this) you can install and run whatever applications you want. Vista and Windows 7 close this "loophole" by monitoring all the applications currently running whenever a media file with DRM is playing. If Vista or Windows 7 detects an unapproved application running in the background, your song or video will simply stop playing. In practice, the encryption on most popular DRM schemes (including DVD and Blu ray) has been cracked, and DRM-free copies of almost any piece of film or music are available on the internet. But users of Windows 7 and Vista still have code running on their computer—at all times—that is trying to limit their basic right to share media with each other and their power to build libraries.

These restrictions have gone beyond what many would expect. For example, at the request of NBC, Microsoft prevented Windows Media Center users from recording television shows that NBC would rather you didn't, even though this kind of recording is an included feature of Windows Media Center. They claimed that they were just following FCC regulations, though the Second Circuit Court of Appeals ruled that the FCC has no authority to make such regulations.

Microsoft even adds DRM in contexts where media companies have largely given up on it. This year, after every major online music store went DRM-free, Microsoft launched a DRM-encumbered music store for mobile phones — this music service has one particularly charming limitation: many people switch cellphones every 6 months to a year, but there is no way to transfer songs from one phone to the next. If you switch phones every 6 months, then you lose your music every six months. But more importantly, this is a level of DRM that music companies are no longer demanding, indicating that Microsoft has its own aim in promoting DRM: lock-in. Because DRM creates artificial incompatibility, it is the perfect tool for tying users of a service to a particular product. When people buy music from a Microsoft service, they cannot use any other music players (like the iPod, for example). Even when Microsoft launched its own "Zune" music player, the Zune did not play tracks with Microsoft "Plays for Sure" DRM sold by other music services (including the MTV URGE Music Service built in to Windows Media Player 11). Pressure from big media companies is not the only reason Microsoft pushes DRM; lock-in is central to Microsoft's business strategy and DRM is a great way to pursue it.

Microsoft is not the only company guilty of this. Apple, via its iTunes software, and its Macintosh, iPod, iPhone and Apple TV devices also imposes DRM on users. Adobe and Sony also impose DRM on users. But Microsoft is a particularly aggressive user of DRM, and the integration of DRM at the deepest levels of Windows 7 is a key reason not to buy it.

Free software, by its very nature, does not support DRM — if DRM were added to free software, the users and developers would work around it and remove it.

Further reading: Opposing Digital Rights Management