Microsoft has denied antitrust claims from Opera Software that the software giant is abusing its dominant market position to lock users into the Internet Explorer Web browser. Opera, based in Norway, announced last week that it had filed an antitrust complaint with the European Commission, alleging that Microsoft is abusing its dominant position by bundling IE with the Windows operating system. Bundling IE with Windows means people have no choice in receiving it and only afterward have the option of deleting it or using an alternative product as the default browser, Opera said. Opera also claimed that Microsoft is hindering interoperability by not following accepted open Web standards. Microsoft struck back last Friday, indicating that it would not willingly unbundle IE from Windows. "We believe the inclusion of the (IE) browser into the operating system benefits consumers, and that consumers and PC manufacturers are already free to choose to use any browsers they wish," a Microsoft representative said.