Millions of Windows users could potentially be affected by a computer glitch that results in a “black screen of death” after a security update is made, UK security firm Prevx reported in a blog post.
Users that are affected log on to find there is no desktop, task bar, system tray or side bar. “Instead you are left with a totally black screen and a single My Computer Explorer window,” reads the post. “Even this window might be minimized making it hard to see.”
Investigation Under Way
The cause of the problem — which apparently affects a wide range of Windows machines from Windows 7 to Windows NT — is unclear. At least 10 different scenarios might trigger the black screen, Prevx said, including a change in the Windows operating system lockdown of registry keys.
This change has the effect of invalidating several key registry entries if they are updated without consideration of the new ACL (access control list) rules being applied. The rule change does not appear to have been publicized adequately, if at all, with the recent Windows updates, the blog said.
Prevx did not return a call from TechNewsWorld by press time.
Microsoft is reportedly investigating the issue but apparently does not believe its support organization is at fault. There are no known problems similar to this one documented in the company’s security bulletins.
Microsoft did not return a call from TechNewsWorld by press time.
There is a procedure that might fix the problem, according to Prevx, although it admits it may not work given the uncertainty of the cause.
The firm provides step-by-step instructions in its blog.
It’s as good a solution as any in the absence of additional details from Microsoft, Christopher Ciabarra, president of Network Intercept, told TechNewsWorld.
“It’s hard to say what could be wrong and what could fix this just based on the limited information available right now,” he said, noting that a corrupted profile also could be a cause.
What it doesn’t appear to be is a copy-protection issue, Ciabarra said.
Several years ago, Microsoft would disable desktops of users who were found to have copied software. Users would log on and find the black screen in place of their usual desktop, he said, “but it stopped doing that and just began issuing warnings instead.”