[LATEST UPDATE: Prevx backpedals on cause of problem. Says problems NOT caused by Windows updates.
"Having narrowed down a specific trigger for this condition we've done quite a bit of testing and re-testing on the recent Windows patches including KB976098 and KB915597 as referred to in our previous blog. Since more specifically narrowing down the cause we have been able to exonerate these patches from being a contributory factor.
"We have always strongly recommended keeping Windows and all other software up-to-date to reduce the window for exploitation by new threats. We'll keep you updated with further progress if we find anything new.
"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."
Any problems you're having regarding a Black Screen of Death have nothing to do with November's Windows Updates.
The "Black Screen of Death" problem which was widely reported in the tech media yesterday doesn't seem to be the huge "HELP! The sky is falling in on us!!!" problem that is was made out to be yesterday. In fact, at best I can only find a small handful of documented cases.
UK security company Prevx posted details of the problem on its website:
Firstly, there appears to be many causes of the black screen issue. The symptoms are very distinctive and troublesome. After starting your Windows 7, Vista, XP, NT, W2K, W2K3 or W2K8 PC or server the system appears normal. However, after logging on 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. Even this window might be minimized making it hard to see.
The folks at Prevx also posted a possible fix for this problem.
[UPDATE: Turns out this is now all nonsense ...]
Now, I'm not doubting that the problem exists. I have found a small thread about in on Microsoft's TechNet site, and Microsoft has confirmed that it is investigating the problem. The problem seems to be associated with an update, MS09-065, that was released last month. However, none of this seems to warrant the copious amounts written (and emails I've received) about this bug over the past 24 hours.
It seems we can all stop panicking now. In fact, there was little to panic about in the first place.
[UPDATE x2: Microsoft says this problem has nothing to do with updates:
Our comprehensive investigation has shown that the November security updates, the Microsoft Malicious SoftwareRemoval Tool, and the non-security updates we released through Windows Update in November do not make any changes to the registry as claimed. We do not believe Microsoft Updates are related to the behavior described in these reports.
Official statement here.]
[UPDATE: I'm now hearing from people affected by this issue, so there's no doubt that it's real. I've also heard from a couple of people who say that the Prevx download didn't fix the problem for them, so there may be more than one issue at work here, or some mystery factor at work. Also, it's odd that several of the people who have been in touch with me say several of their machines were affected - may be that some change or setting or software that causes this problem to occur.
I've tried replicating the problem, so far with no success.]