Prevx was alerted to the problem by users of its security software last week, Morris said. Microsoft apparently made changes to the Access Control List (ACL), a list of permissions for a logged-on user. The ACL interacts with registry keys, creating visible desktop features such as a sidebar.

Microsoft has investigated reports that its November security updates made changes to permissions in the registry that are resulting in system issues for some customers," Christopher Budd, Microsoft's security spokesman, said in an e-mail. "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."

The conditions under which the actual black screen is triggered are spasmodic," admitted Dave Kennerley of Prevx's support team in an update to the original blog post of last week. "Some test systems always trigger the condition, others are less consistent. The windows patches which seem common to the issue arising are & KB915597 and KB976098 ."

"Received a patch on Nov 24 or 25. Upon reboot the computer has a totally black screen," said a user identified only as "General Zod" in a message added to the thread around 2:30 p.m. ET today. "Not even the BIOS startup stuff appears."

A couple of days ago we wrote about the Black Screen of Death, a problem that caused Windows-based machines to freeze and lock out users, leaving them teary-eyed and black-screened.

The issue, however, doesn’t seem to be a common one, nor is it tied to Microsoft’s security updates, as we’d previously thought. In fact, UK security company Prevx, who pointed out the issue (and actually offered a software fix), admitted that the problem is likely caused by malware and not by Microsoft’s error.

Prevx’s CEO Mel Morris wrote a blog post, apologizing to Microsoft for the inconvenience. From the post:

“The issue appears to be related to a characteristic of the Windows Registry related to the storage of string data. In parsing the Shell value in the registry, Windows requires a null terminated ‘REG_SZ’ string. However, if malware or indeed any other program modifies the shell entry to not include null terminating characters, the shell will no longer load properly, resulting in the infamous Black Screen with the PC showing only the My Computer folder.”

The folks at Microsoft, understandably, aren’t happy. Chief Security Advisor of Microsoft EMEA Roger Halbheer fired at Prevx on his blog, saying:

“Looking at that, you should now make your risk assessment and decide which source you want to trust. For me, the ultimate source for information you should build your assessment on is neither Twitter (Twitter) nor your brother’s sister in law’s father’s brother (unless he works for Microsoft’s security) but our website.”

While this particular case was a false alarm, Halbheer forgets to point out that if we had listened exclusively to what Microsoft says when it comes to security issues in the past, we would have missed quite a lot of them. As always, don’t believe everything you read, see or hear, but also don’t immediately write off any news that doesn’t come from an official source.

We apologize to Microsoft for any inconvenience our blog may have caused. This has been a challenging issue to identify. Users who have the black screen issue referred to can still safely use our free fix tool to restore their desktop icons and task bar.

Kernel panic izaziva nesto sta trci u kernel modu, nema veze malware sa tim.
Besides, i da neki malware pozove sistemske pozive koji ce natjerat neki kernel modul da pukne...opet Microsoft kriv jer mu pucaju moduli.