Protecting Your Digital Rights In Microsoft Windows XP


Windows Media Player is designed to deal gracefully with media files that are licensed using Microsoft’s Windows Media Digital Rights Management (DRM) technology—that is, digital content whose use is governed by a licensing agreement with the content provider. The license associated with a file, which protects the provider against illegal distribution of the media item, specifies how you can use the file and for what period of time. Licensed files are encrypted using digital signatures. The terms of the license are determined by the content vendor; Windows Media Player enforces the terms of that license agreement.

When you download a media item—a song or a movie clip, for instance—from the Internet, the content provider might provide you with a license. Alternatively, if you play an unlicensed file that requires a license, the Player tries to obtain the license. You might have to register or pay for the license at this time.

Windows Media DRM licenses may be for an indefinite period of time or may expire after some period of time. In some cases, a license will allow you to play the media item only on the computer on which the item was obtained. In other cases, a license allows you to copy or move the item to other computers (but not necessarily to CDs). If the protected content originated on a CD (that is, if you copied protected content from a CD to your hard disk), you typically are permitted to copy the content onto another CD but not to other computers.

Copying to SDMI-compliant portable devices is typically restricted by the same terms that apply to the use of the item on the computer where it was downloaded. (SDMI stands for Secure Digital Music Initiative, a forum that seeks to establish technology specifications for protecting the property rights of digital content providers. For more information, see the forum’s Web site at http://www.sdmi.org.)

You can read the terms of an item’s license by examining the item’s properties dialog box. Locate the file in Windows Media Player or in Windows Explorer (usually you’ll find it in My Music), right-click it, choose Properties from the shortcut menu, and click the License tab.

Figure shows the License tab for a downloaded music file. Alternatively, if the file is included in the Player’s media library, you can right-click it there, choose Properties, and click the License Information tab. The same information appears in both places.


Figure. You can read the terms of a media item’s license by displaying its properties dialog box, either in Windows Explorer or in the Player’s Media Library.

If you have bought licenses that allow you to play the items for an indefinite period of time on your own computer, that doesn’t mean you can never move the media items to another computer. You can move them (giving up your privileges on the current computer, of course), but only if you have backed up your licenses. When you move the media to a new computer, you restore the licenses on the new computer.