The European Union moved a step closer to wrapping up its long-running antitrust case against Microsoft ( MSFT) Monday, winning approval from member countries on a decision that could require the software behemoth to change its Windows operating system.

The European Union's 15 member states unanimously backed the European Commission's draft decision, wire services reported. The European Commission, the executive body of the EU, has charged Microsoft abused the dominant position of its operating system to corner the media-player market by embedding its Media Player in Windows. The commission has also charged Microsoft with using its Windows dominance to gain an advantage in the server market.

The draft decision would require Microsoft to ship two versions of Windows to computer makers -- one with Media Player included with Windows and another without Media Player, according to wire reports. It also would require Microsoft to share more information about Windows with rivals -- for a royalty charge -- to open up competition in the server market.

The European Commission also could charge Microsoft up to 10% of annual revenue, or roughly $3 billion. Although substantial, that would not be a devastating hit to Microsoft, whose cash hoard has surpassed $50 billion.

The decision is slated to receive final review by European regulators on March 15 and 22, with a final decision expected a day or two after the last session.

Microsoft has cited the antitrust case in Europe as a major obstacle to a decision on what to do with its enormous cash stash. Although Microsoft could still fight the EC decision in court, investors are hoping some resolution prompts the company to issue a larger dividend.

Microsoft shares were recently down 20 cents, or 0.8%, to $25.19.