Following an internal investigation, Microsoft has confirmed that its November security updates are not the cause of end-user problems in its Windows operating systems.
The problem, dubbed the "black screen of death", was highlighted in a blog post by UK-based security firm Prevx, who suggested that Microsoft's own security update could be the root cause. The firm indicated that "millions" of users could be affected, adding that the problem could arise on numerous Windows operating systems - including the latest release, Windows 7.
In response, Microsoft's own investigation has revealed that third-party malware is likely to blame. "Our November Security Updates are not making changes to the system that these reports say are responsible for these issues," said the company in a statement.
"We’ve conducted a comprehensive review of the November Security Updates, the Windows Malicious Software Removal Tool, and the non-security updates we released through Windows Update in November. That investigation has shown that none of these updates make any changes to the permissions in the registry. Thus, we don’t believe the updates are related to the “black screen” behaviour described in these reports."
"However, we do know that “black screen” behaviour is associated with some malware families such as Daonol," it adds.
Prevx, who originally stated that the cause of the black screen "appears to be a change in the Windows Operating Systems lock down of registry keys," has since backtracked and now also believes malware is to blame.
"We apologise to Microsoft for any inconvenience our blog may have caused," said the security firm in its latest blog post.