Microsoft on Tuesday admitted that it failed to roll out the mandated "browser screen choice" (BCS) to users of Windows 7 service pack 1 (SP1), a move that could result in European Commission sanctions.
In a statement, Microsoft blamed a "technical error" for the oversight.
"While we believed when we filed our most recent compliance report in December 2011 that we were distributing the BCS software to all relevant PCs as required, we learned recently that we've missed serving the BCS software to the roughly 28 million PCs running Windows 7 SP1," the company said.
The controversy dates back to 2009, when the European Commission announced that Microsoft violated European competition law by bundling its Internet Explorer browser with Windows. As a result, Microsoft said it would ship a version of Windows 7 with a "browser ballot" that would allow users to select which browser they wanted during the OS installation process. The EU approved that plan in Dec. 2009 and it started rolling out two months later.
Earlier this year, the commission notified Microsoft that it had received reports of people not seeing the BCS. Microsoft said it investigated and discovered the SP1 error. A fix started rolling out to PCs running Windows 7 SP1 on July 3, and Microsoft expects to complete that rollout by week's end.
Microsoft said it has retained an outside firm to investigate what happened, and offered to extend the period it was required to display the BCS by 15 months.
Users of Windows XP, Vista, and the original version of Windows 7 were not affected, and Microsoft said that about 90 percent of the PCs that should have seen the BCS did, in fact, see it.
"We recognize, however, that our obligation was to distribute the BCS to every PC that should have received it," Microsoft said. "Therefore, we have moved as quickly as we can to address the error and to provide a full accounting of it to the Commission."
It remains to be seen if the commission will be forgiving.
"We take compliance with our decisions very seriously. And I trusted the company's reports were accurate. But it seems that was not the case, so we have immediately taken action," Joaquín Almunia, vice president of the Commission in charge of competition policy, said in a statement. "If following our investigation, the infringement is confirmed, Microsoft should expect sanctions."
What was behind the "technical error"? According to Microsoft, its Windows Update system uses a "detection login" to determine which software updates - like the BCS - to distribute to which PCs.
"Unfortunately, the engineering team responsible for maintenance of this code did not realize that it needed to update the detection logic for the BCS software when Windows 7 SP1 was released last year," Microsoft said. "As a result of this error, new PCs with Windows 7 SP1 did not receive the BCS software as they should have."