Just a few days after launching a new antitrust probe against Microsoft for failing to live up to an agreement to provide Windows users with adequate access to rivals’ Internet browsers, the European regulators have broadened the scope of the investigation.

In 2009, Microsoft signed an agreement that was meant to make the Redmond-based software giant to provide Windows users with the browser choice screen (BCS) to let users to choose a browser other than Internet Explorer.

The European Commission decided to launch a new antitrust probe against Microsoft after it released Windows 7 Service Pack 1 without BCS in February 2011. Since then, the regulators have added Windows 8 OS to the probe as the final version of Windows 8 and Windows RT operating systems are reportedly also missing the BCS.

The new probe was announced just a few weeks after a European court sustained most of a massive fine that the European commission had imposed on the Redmond firm in 2008 for failing to fully comply with an order covering technical documents that the company was supposed to share with its rivals.

Meanwhile, Microsoft reported its first ever quarterly loass due to a 6.2 billion write-down related to its non-performance of online advertising business aQuantive.