Microsoft Corp designs, develops and markets a wide range of software for different types of computer equipment. That software includes operating systems for personal computers (‘PCs’), known as Windows, work group server operating systems, known as Windows Server, and streaming media players, known as Windows Media Player. Microsoft also provides technical assistance for its software.

Sun Microsystems, Inc., which supplies, inter alia, workgroup server operating systems, lodged a complaint with the Commission.

In its complaint, Sun Microsystems complained that Microsoft had refused to supply it with the information and technology necessary to allow interoperability of its work group server operating systems with Windows.
The Commission did sent Microsoft a first statement of objections. That statement of objections focused essentially on questions of the interoperability between Windows PC operating systems and operating systems for other suppliers’ servers (‘client-to-server interoperability’).

Hereinafter the Commission launched on its own initiative an investigation into Microsoft’s ‘Windows 2000’ PC and work group server operating systems and into Microsoft’s integration of its ‘Windows Media Player’ software into its PC operating systems.

That investigation culminated in a second statement of objections being sent to Microsoft. In that statement of objections, the Commission reiterated its previous objections concerning client-to-server interoperability. The Commission also addressed a number of questions relating to interoperability between work group servers (server-to-server interoperability). Last, the Commission raised certain questions relating to the integration of Windows Media Player into Microsoft’s PC operating systems.

Later on, the Commission sent Microsoft a third statement of objections intended to supplement the two previous statements and to give an indication of the remedies which it proposed to order.

In assessing Microsoft’s conduct, the Commission first identified three distinct product markets, consisting of client PC operating systems, work group server operating systems and streaming media players. Second, the Commission considered that each of those markets was worldwide.

Third, the Commission found that Microsoft held a dominant position on the client PC operating system market and the work group server operating system market.

Fourth, it concluded that, by its conduct on those two markets, Microsoft was infringing Article 82 EC. First, it considered that Microsoft was abusing its dominant position by refusing to supply the interoperability information and to authorise its use for the development and distribution of products competing with its own products on the work group server operating system market during the period October 1998 to the date of notification of the contested decision (Article 2(a) of the contested decision). The Commission also considered that Microsoft was abusing its dominant position by making the availability of the Windows client PC operating system conditional on the simultaneous acquisition of Windows Media Player during the period May 1999 to the date of notification of the contested decision (Article 2(b) of the contested decision).

Fifth, the Commission imposed a fine of EUR 497 196 304 on Microsoft (Article 3 of the contested decision).
Sixth, it ordered Microsoft to bring the abovementioned infringements to an end, to refrain from any conduct having the same or equivalent object or effect and to implement a series of remedies within certain periods (Articles 4 to 8 of the contested decision).

By application lodged at the Registry of the Court of First Instance, Microsoft brought an action for annulment of the contested decision or, in the alternative, annulment of or reduction in the fine.