A glitch in Microsoft's browser ballot is being blamed by Mozilla for the loss of nine million Firefox downloads.
Mozilla says the glitch that dropped the browser choice option from Windows 7 caused them major losses. According to a blog post from the company's general counsel Harvey Anderson, Mozilla lost 63 per cent of its daily Firefox downloads because of Microsoft's error.
"The 2009 Commitments adopted by Microsoft were a foundational part of the remedy developed by the Commission to resolve Microsoft's competition violations in European Community (EC) countries," said Anderson.
"A key part of the remedy was Microsoft's commitment to present the browser ballot screen to Windows users through vehicles like the Windows 7 Service Pack 1. Earlier this year, we learned that Microsoft failed to fully comply with the browser choice ballot screen obligation for nearly 15 months," added Anderson.
In 2009 Microsoft began putting an option in its operating systems that let users choose what web browser they wanted to run. The move was made following allegations that Microsoft was giving its products an unfair advantage by pre-installing Internet Explorer in Windows.
Earlier this year, a glitch found inside the Windows 7 service pack 1 update caused the browser ballot option to be cut from the operating system. The glitch caused Microsoft to be fined by the European Union.
According to Anderson, the glitch also cost Mozilla some of its market share. Anderson reported that Firefox downloads dropped over the 15-month period that Microsoft allowed the glitch to stay in the wild. He said Firefox downloads jumped over 150 per cent per day following the fix.
"After accounting for the aggregate impact on all the browser vendors, it seems like this technical glitch decreased downloads and diminished the effectiveness of the remedy ordered in the 2009 Commitments," continued Anderson.
Mozilla's browser news follows Microsoft's release of its latest Windows 8 operating system. The new Windows was released earlier this month and, according to Microsoft, has already seen over four million downloads.