In a nutshell, this is the dilemma Microsoft faces as it prepares to launch Windows Vista. By any standard, Vista's new DRM capabilities -- aimed at protecting the rights of content owners by placing limits on how consumers can use digital media -- hardly qualify as a selling point; after all, it's hard to sing the praises of technology designed to make life harder for its users.

Microsoft itself defines digital rights management in straightforward terms, as "any technology used to protect the interests of owners of content and services." In theory, it's an easy concept to grasp; in practice, however, modern DRM technologies include a multitude of hardware-, software- and media-based content-protection schemes, many of which have little or nothing in common.

DRM at the hardware level

Vista's DRM technologies fall into several distinct categories, all of which are either completely new to the operating system or represent a significant change from the technology found in previous versions of Windows. The Intel-developed Trusted Platform Module (TPM) makes DRM harder to circumvent by extending it beyond the operating system and into the PC's hardware components.

TPM is used with Vista's BitLocker full-drive encryption technology to protect a PC's data against security breaches. A TPM microchip embedded on the PC's motherboard stores unique system identifiers along with the BitLocker decryption keys. If a system is tampered with -- for example, if the hard drive is removed and placed in a different machine -- TPM detects the tampering and prevents the drive from being unencrypted.