Microsoft has confirmed reports that it is currently investigating a problem that has become known as the 'black screen of death' which is affecting its latest operating system, Windows 7.
The problem, which could be linked to a recent security update, means that users of Windows 7 face seeing a black screen after logging in to the operating system.
Microsoft says that it is investigating reports that the latest security update, issued on November 25, is the cause of the problem.
There are also reports that other Microsoft operating systems, such as Vista or XP, could also be affected by this recent bug.
"Millions" of people are potentially affect by this say software firm Prevx, who have issued a fix for the problem. David Kennerley, who works with the company, wrote in a blog, "Users have resorted to reloading Windows as a last ditch effort to fix the problem. We hope we can help a good many of you avoid the need to reload."
However, it is reported that the fix will not work for everyone.
Mr Kennerley goes on to say, "There can be many causes. But if your black screen woes began in the last two weeks after a Windows update or after running any security program (including Prevx) to remove malware during this time then this fix will have a high probability of working."
He also said that they had identified "at least 10 different scenarios which will trigger the same black screen conditions. These appear to have been around for years now," he said.
Other operating systems that could potentially be affected by this problem are some editions of Windows 7, Vista, XP, NT and Windows 2000.
Microsoft recommends that anyone who is affected by this issue should contact the company's customer service line.
However, a spokesperson for the company said that reports did not match any issues documented by the firm and they have not issued a fix.
The problem causes the desk-top, task bar, system tray and sidebar to completely disappear.
The term 'black screen of death' is a play on the 'blue screen of death', a well known phenomenon for users of Microsoft's operating systems who see this when the systems crash.