On Friday, Prevx, a maker of antivirus software, attributed some of these black screen crashes to a recent Window operating system change that locked down Windows registry keys.

But Microsoft insists that's just wrong.

"Microsoft has investigated reports that its November security updates made changes to permissions in the registry that that are resulting in system issues for some customers," said Christopher Budd, Microsoft security response communications lead, in an e-mailed statement. "The company has found those reports to be inaccurate and our comprehensive investigation has shown that none of the recently released updates are related to the behavior described in the reports. While we were not contacted by the organization [that] originally made these reports, we have proactively contacted them with our findings."