Washington: A Spanish group of open-source software developers has accused Microsoft of making it difficult for users of Windows 8 to install alternatives.
The group of 8,000 Linux developers filed a complaint to the European Commission about a mechanism that locks out other operating systems.
Its 14-page complaint, the Hispalinux group said users needed to request digital keys from Microsoft to install another operating system.
According to an English news website, Microsoft said the mechanism was a security feature.
Microsoft said in a statement that Unified Extensible Firmware Interface (UEFI) Secure Boot in Windows 8 is an industry standard aimed at improving computer security and the approach has been public for some time.
The firm said they are happy to answer any additional questions, but are confident their approach complies with the law and helps keep customers safe.
According to the report, earlier this month the commission fined the firm 561m euros for failing to offer users a choice of web browser.