European regulators have apparently raised an eyebrow at complaints that Microsoft will be banning rival browsers from Windows RT.

Mozilla moaned last week that it would not be possible to run Firefox on Windows RT. The European Commission warned hat an agreement it struck with Microsoft in 2009 to regulate its behaviour applied only to "client PCs." This means that Microsoft could be off the hook as Windows RT is designed for tablets.

Antoine Colombani, the Commission's spokesman for competition  said that the Commission was aware of these allegations and will remain vigilant that Microsoft fully complies with its commitments under the Commission's 2009 decision on browsers.