The company that sparked off the EU's antitrust investigation into Microsoft in Europe, Opera Software, has slammed the way that Microsoft will remove IE8 from Windows 7.

Last week, Microsoft shared a bit of technical information about how it is stripping IE8 from Windows 7 to create the "E" editions for the European Union market.

"The only functional difference is that the Internet Explorer 8 component is not available," said Arik Cohen, a Microsoft program manager in a Q&A on the company's Windows blog. "This is the same component that your users can turn off in the 'Turn Windows features on and off' control panel in the Windows 7 RC build."

All other parts of IE will remain in the E editions, said Cohen, "since they are part of the Windows core."

The "Turn Windows features on and off" feature refers to the kill switch option Microsoft added to Windows 7 in March. Then, Microsoft managers confirmed that the new operating system would offer user settings for disabling, but not deleting, a host of bundled applications, including IE8. "If a feature is deselected, it is not available for use," said Jack Mayo, a program manager on the Windows team. "This means the files (binaries and data) are not loaded by the operating system and not available to users on the computer."

Files are not actually deleted from the PC, however, so users can later reactivate the disabled applications, said Mayo.

Flipping a switch to simply make IE8 unavailable is not enough for Opera, the browser builder that complained to EU regulators in late 2007. Its complaint led the government's antitrust agency to charge Microsoft in January with shielding IE from competition.

"Microsoft's minor technical tweak will not restore browser competition on the desktop," said Hakon Wium Lie, Opera's chief technology officer, in an email.

Opera has previously expressed dissatisfaction with Microsoft's decision to dump IE8 from Windows 7. In June, when Microsoft announced the E editions, Lie was sceptical, even though it was unclear at the time exactly what part of the browser would be removed. "The rendering engine will remain," Lie argued then. "Who knows what Windows Update would do? You could wake up in the morning and see all of IE8 there again." Microsoft may have felt forced to leave parts of IE within Windows, since some of the OS's functionality, particularly Windows Update, likely depends on those components.

A month ago, Microsoft acknowledged that its unilateral move might not satisfy critics, including EU officials. "Our decision to only offer IE separately from Windows 7 in Europe cannot, of course, preclude the possibility of alternative approaches emerging through Commission processes," Dave Heiner, Microsoft's deputy counsel, said on 11 June.

While the EU has not yet ruled - Microsoft dropped an oral hearing slated for early June because of scheduling conflicts - but Lie said that as far as Opera is concerned, turning off IE but leaving bits and pieces in Windows 7 isn't enough. "At Opera, we'd like to give users access to more browsers, not fewer," he said.

Opera wants the EU to order Microsoft to insert a ballot screen into Windows; the screen would offer users several browser choices that would then either be activated - if all were pre-installed on the machine - or downloaded and installed.

Regulators also have hinted that the ballot screen is its preferred solution. "A potential remedy ... and which would not require Microsoft to provide Windows to end-users without a browser, would be to allow consumers to choose from different web browsers presented to them through a 'ballot screen' in Windows," the European Commission said in a 12 June statement.