Users who customize their own versions of Linux, or use a generic OS that does not come with a key, may not be able to run these OSes on machines requiring this secure booting process, Garrett . Nor would there be any guarantee that OEMs (original equipment manufacturers) even provide the ability for users to add their own keys, or give users the option to run other OSes without a key.

Garrett's blog post subsequently in the trade press and Linux user communities.

Responding to the controversy on Thursday, Microsoft has denied that the intent was to shut out Linux. Although he did not mention Linux by name, Steven Sinofsky, president of the Windows and Windows Live Division, that some of those commenting have used details of the new plan to "synthesize scenarios that are not the case."

The rest of the posting, authored by Mangefeste, noted that Microsoft is concerned only that Windows 8 be protected in a secure boot loader, and that OEMs are free to build in the option of disabling secure boot for running OSes without keys. Other OS providers are responsible for providing their own keys.

"For the enthusiast who wants to run older operating systems, the option is there to allow you to make that decision," Mangefeste wrote. "However, [disabling secure boot] comes at your own risk," he added.